Answer:
The answer is = −70s+63
Step-by-step explanation:
7(1−10s+8)
=(7)(1+−10s+8)
=(7)(1)+(7)(−10s)+(7)(8)
=7−70s+56
=−70s+63
19) 15/a = 3/2
Start by cross multiplying....
3a = 30
Divide both sides 3
a = 10
21) 2/7 = 4/d
2d = 28
d= 14
23) 8/p = 3/10
80 = 3p
p = 26.66
25) 2 / -5 = 6/t
2t = -30
t = -15
For the answer to the question above, <span>f x is the number of days she works, she'll earn $90x </span>
<span>After buying the laptop, she'll have $90x - $700 left over, which will pay for ($90x - $700) / $150 days of travel. So we have y = ($90x - $700) / $150 = (9x - 70) / 15 = 0.6x - (14/3) </span>
<span>Note that y can't be negative. Also, if y = 0, then Emma doesn't get to travel at all, so we should avoid that. So we have: </span>
<span>0.6x - (14/3) > 0 </span>
<span>0.6x > 14/3 </span>
<span>x > (14/3) / 0.6 </span>
<span>x > 70/9 </span>
<span>The question says that x can be up to 40, so the domain is 70/9 < x <= 40 </span>
<span>That's approximately 7.777... < x <= 40 </span>
<span>Multiply those numbers by 0.6 and then subtract 700 to get the range: </span>
<span>0 < y <= 58/3 </span>
<span>That's approximately 0 < y <= 19.333</span>
