<span>2(a+b)=c
2a + 2b = c
2b = c - 2a
b = (c - 2a)/a
answer
</span><span>D. b = (c−2a)/2 ; distribute 2 to get 2a+2b, subtract 2a, then divide by 2.</span>
When you simply the expression it’s 16
Lizzie has 18 dimes and 12 quarters
<em><u>Solution:</u></em>
Let "d" be the number of dimes
Let "q" be the number of quarters
We know that,
value of 1 dime = $ 0.10
value of 1 quarter = $ 0.25
Given that LIzzie has 30 coins
number of dimes + number of quarters = 30
d + q = 30 ---- eqn 1
Also given that the coins total $ 4.80
number of dimes x value of 1 dime + number of quarters x value of 1 quarter = 4.80

0.1d + 0.25q = 4.8 ------ eqn 2
Let us solve eqn 1 and eqn 2
From eqn 1,
d = 30 - q ---- eqn 3
Substitute eqn 3 in eqn 2
0.1(30 - q) + 0.25q = 4.8
3 - 0.1q + 0.25q = 4.8
0.15q = 1.8
<h3>q = 12</h3>
From eqn 3,
d = 30 - 12
<h3>d = 18</h3>
Thus she has 18 dimes and 12 quarters
7x - 5 = 30
* add 5 to both sides
7x = 30 + 5
7x = 35
* divided both sides by 7
(7/7)x = 35/7
<u><em>x = 5</em></u>