Page 100 - Math Course 2 (Book 1)

Multiplication by a Monomial

MO. 3 - L8b

Solving Equations Involving
Polynomials

Let’s Begin Polynomials on Both Sides

Real World Example Examples

Solve
ENTERTAINMENT
Admission to the Super Fun Amusement Park is $10. b(12 + b) – 7 = 2b + b(–4 + b).
Once in the park, super rides are an additional $3 each b(12 + b) – 7 = 2b + b(–4 + b) Original equation.
and regular rides are an additional $2. Sarita goes to
the park and rides 15 rides, of which s of those 15 are 12b + b – 7 = 2b – 4b + b 2 Distributive
2
super rides. Find an expression for how much money Property.
Sarita spent at the park.
2
2
12b + b – 7 = –2b + b Combine like
Words terms.
Amount = admission + super • $3 per + regular • $2 per 2
of money rides ride rides ride 12b – 7 = –2b Subtract b from
each side.

Variables 12b = –2b + 7 Add 7 to each
If s = the number of super rides, then 15 – s is the side.
number of regular rides. Let M be the amount of
money Sarita spent at the park. 14b = 7 Add 2b to each
side.

Equation b = 1 Divide each side
2
M = 10 + s • 3 + (15 – s) • 2 by 14.

= 10 +3s + 15(2) – s(2) Distributive Property 1
Answer
2
= 10 + 3s + 30 – 2s Simplify.

= 40 + s Simplify. Check
b(12 + b) – 7 = 2b + b(–4 + b) Original equation.
An expression for the amount of
money Sarita spent in the park is
Answer 1 1 1 1 1 1
40 + s, where s is the number of 12 + –7 = 2 + –4 + b =
super rides she rode. 2 2 2 2 2 2

Evaluate the expression to f nd the cost if Sarita rode 9 1 25 –7 = 1 + 1 – 7 Simplify.
super rides. 2 2 2 2

40 + s = 40 + 9 s = 9 25 7
= 49 Add. 4 –7 = 1– 4 Multiply.

3 3
Answer Sarita spent $49. – 4 = – 4 Subtract.

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