1. 79% Take 100 x 21%=21, then subtract 21 from 100 = 79
2. $138 Take 1200 x 11.5%= $138
2x + 5y = -3 ⇒ 2x + 5y = -3
1x + 8y = 4 ⇒ <u>2x + 16y = 8
</u> -<u>11y</u> = <u>-11 </u>
-11 -11
y = 1
2x + 5(1) = -3
2x + 5 = -3
<u> -5 -5</u>
<u>2x</u> = <u>-8</u>
2 2
x = -4
(x, y) = (-4, 1)
2x + 1y = 7 ⇒ 2x + 1y = 7
1x - 2y = -14 ⇒ <u>2x - 4y = -28</u>
<u>5y</u> = <u>35</u>
5 5
y = 7
2x + 7 = 7
<u> -7 -7</u>
<u>2x</u> = <u>0</u>
2 2
x = 0
(x, y) = (0, 7)
Answer:
4 hours
Step-by-step explanation:
Since the company was able to produce 15 book in 3 hours, that mean they produce 5 book every hour. So adding 5 more books to 15 to get 20 means that you add one more hour. So it would be 4 hours! hope this helps!:)