Equivalent Equations Practice AK

1. 487.2 beanies

$\eqalign{P(c)&=60c-35c-26\\P(25)&=60(25)-35(25)-26\\&=25(25)-26\\&=625-26\\599&=1.25b-10\\+10&=\quad +10\\609&=1.25b\\b=487.2}$

2. \$450

$\eqalign{45+2.70(\dfrac{m}{20})&=300+.05m\\-45\qquad \qquad&=-45\\2.70(\dfrac{m}{20})&=255+.05m\\\times 20 &= \times 20\\2.70m&=20(255+.05m)\\2.70m&=5100+m\\-m&=\quad-m\\1.70m&=5100\\m&=3000\\A(3000)&=300+.05(3000)\\A(3000)&=450}$

3. \$370

$\eqalign{150+.55x&=230+.35x\\-.35x&=\quad -.35x\\150+.2x&=230\\-150 \quad &=-150\\.2x&=80\\x&=400\\A(400)&=150+.55(400)\\A(400)&=370}$

4.He can buy 9 donut holes.

$\eqalign{\text{mom}&=2.50+.90\\\text{son}&=.35x\\2.50+.90&\geq .35x\\3.40 &\geq .35x\\9.71 &\geq x}$

5. After 4 months.

$\eqalign{\text{YMCA}&=100+795m\\\text{church}&=1.03(800m)\\100+795m&=1.03(800m)\\100+795m&=824m\\-795m&\quad -795m\\100&= 29m\\m&=3.44}$