High School Modules > Algebra by Gregory A. Moore
Exponent Problems
The rules of exponents, and solving problems with exponents.
[Directions : Execute the Code Resource section first. Although there will be no output immediately, these definitions are used later in this worksheet.]
0. Code
| > | restart; |
| > | txln := `\n____________________________________________________________________________`: |
1. Rules of Exponents
Here are some of the main rules of exponents, and their application in Maple.
| > | print(cat(txln,`\n1. Product Rule`)); a^n * a^m: %= simplify(%);print(txln); |
| > | 10^5 * 10^2; |
| > | x^5 * x^4; |
| > | y^8 * y^5; |
| > | (x+4)^10 * (x+4)^8; |
| > | x^4 * y^3; `Note that the bases must be the same to use this rule`; |
| > | distance^2 * distance^3; |
| > | print(cat(txln,`\n2. Quotient Rule`));a^n / a^m: %= simplify(%); print(txln); |
| > | 10^9 / 10^6; |
| > | x^14/x^13; |
| > | x^20 / x^23; |
| > | q^100 / q^10; |
| > | (y + 7)^3 / (y+7)^5; |
| > | print(cat(txln,`\n3. Zero Power is One`)); `a^0` = expand(a^0);print(txln); |
| > | 13^0; 813^0; (-29)^0; (3/19)^0; (41239)^0; (3.14159)^0; |
| > | print(cat(txln,`\n4. Power of One is Identity`));`a^1` =simplify(a^1); print(txln); |
| > | 13^1; 813^1; (-29)^1; (3/19)^1; (41239)^1; (3.14159)^1; |
| > | print(cat(txln,`\n5. Power of a Power`)); (a^n)^m = a^(n*m) ; print(txln); |
| > | (x^2)^3; |
| > | (y^10)^5; `Compare with ...`, (y^10)*(y^5),` power of a power product of powers`; |
| > | ((t - 7)^8 )^3 ; |
| > | print(cat(txln,`\n6. Power of Product`)); (a*b)^m = (a^n)*(b^m); print(txln); |
| > | (3*x)^4; |
| > | (8*y)^10; |
| > | print(cat(txln,`\n7. Power of a Product of Powers`)); (a^n*b^m)^m = (a^(n*p))*(b^(m*p)); `(This is a combination of rules 1 and 6.)`; print(txln); |
| > | (x^3 * y^5) ^ 2; |
| > | (x^10 * y^20) ^ 5; |
| > | (17 * M^7) ^ 2; |
| > | (3 * x^10 * y^7) ^ 4; |
| > | (a^2 * b^3 * c^4 * d^5 ) ^ 10; |
| > | print(cat(txln,`\n8. Power of a Quotient`)); (a/b)^n =(a^n)/(b^n); print(txln); |
| > | (3/4)^3; |
| > | (x/2)^5; |
| > | (a/b)^4; |
| > | (3/(x+5))^9; |
| > | print(cat(txln,`\n9. Power of a Quotient of Powers`)); (a^n * b^m)^p = a^(n*p)*b^(m*p); `(This is a combination of rules 2 and 8.)`; print(txln); |
| > | ( x^3 / y^ 5)^2; |
| > | ( 1 / pressure^2) ^ 3; |
| > | (x^10 / 3) ^ 5; |
2. Negative Exponents
There are a few more rules which involve negative exponents.
| > | print(cat(txln,`\n10. Negative Exponent is Reciprocal`)); a^(-n) = 1/a^n; print(txln); |
| > | 3^(-2); |
| > | `Note :`, 9*3^(-2), 9*(1/9); |
| > | x^(-13); |
| > | (-2)^(-3); |
| > | (-2)^(-4); |
| > | (1/7)^(-2); |
| > | print(cat(txln,`\n11. Reciprocal of a Reciprocal is Original`)); 1/a^(-n) = a^n; print(txln); |
| > | 1/(4^(-3)); |
| > | 1/y^(-12); |
| > | 1/(3*x + 2)^(-5); |
| > | `Note : Rules 10 and 11 can both be used on the same problem :`;x^(-4) / y^(-9); |
| > | print(cat(txln,`\n12. Reciprocal of a Fraction is Flipped`)); (a/b)^(-n) = (b/a)^n; print(txln); |
| > | (2/131)^(-1); |
| > | (x/y)^(-1); |
| > | (1000/A)^(-1); |
| > | ( (x+1) / (x+2) )^(-1); |
| > | ( (x^2 + 3*x + 1) / (x^2 + 5*x + 2) )^(-1); |
| > | (( A/B )^(-1))^(-1); |
3. Exponent Problems - Products (Monomials)
When multiplying two monomial expressions, numbers can be multiplied, and the same variables can be multiplied - remember that we learned in Rule #1 that we can only multiply variables with the same base. For example, with two expressions with numbers, x, and y's - you multiply :
- number by number
- x term by x term
- y term by y term
| > | (3 * x^7* y^2) * (4 * x^4 * y^9); |
| > | (5 * x^5 * y^2) * (11 * x^11 * y^(-3)); |
| > | (13 * x^(-3)* y^(-8)) * (4 * x^(-2) * y^(-7)); |
| > | (1440 * x^100* y^100) * (1200 * x^100 * y^(-100)); |
| > | (33 * x^33* y^22) * (4 * x^44 * y^55); |
4. Exponent Problems - Products (Using Distributive Property)
When we multiply a term by a sum or difference we need to use the Distributive Property.
| > | `Distributive Property`; a*(b+c): % = expand(%); |
We distribute the term being multiplied to each of the terms inside the parentheses. Then each of those multiplications is a product of monomials.
| > | (12*x^10)*(14*x^3 - 1): % = expand(%); |
| > | (3*x^2)*(14*x + 21): % = expand(%); |
| > | (2*x^5)*(4*x^5 - x^2): % = expand(%); |
| > | (a^5*b^10)*(10*a^10*b^9 - a^8*b^7): % = expand(%); |
| > | (20*a^5*b)*(13*a^4*b^9 - b^2): % = expand(%); |
5. Exponent Problems - Quotients - The Idea
6. Exponent Problems - Quotients - Using Maple
We can do these problems in Maple too - quite quickly. Try these by hand, and then check to see if your answer agrees with Maple's answer, or is mathematically equivalent.
| > | (36 * x^4 * y^6 ) / (24 * x^5 * y^5); |
| > | (75 * x^10 * y^3 ) / (24 * x * y^5); |
| > | (100 * x * y ) / (45 * x^11 * y^9); |
| > | (32 * x^14 * y^6 ) / (40 * x^5 * y^5); |
| > | (10 * x^(-4) * y^(-6) ) / (12 * x^5 * y^5); |
| > | (33 * x^(-5) * y^6 ) / (22 * x^(-5) * y^(-5)); |
| > | (15 * x^4 * y^(-6) ) / (18 * x^(-4) * y^5); |
| > | ((6 * x^2 * y^3) / (30 * x^4 * y^5 ) ) ^(-1) ; |
| > | ((40*x^2*y^9) / (30*x^(-6)*y^8) )^(-2) ; |
| > | ((27 * x^(-32) * y^19) / (24 * x^(-46) * y^8) )^(-4) ; |
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