<span>The vertex of y=x^2+8x-20 = (-4, -36)</span>
Answer: 
<u>Step-by-step explanation:</u>

£6.72 not sure but think that’s right, because you divide by ten for ten percent and multiply it by two (20%) then add it to £5.60
$312.50 = p x 0.25 x 25
divided by 25
12.50 = p x 0.25
divide by 0.25
50 = principal
Just ask if anything is unclear