Answer:
9.21954446 (but round to what ever place is required)
Step-by-step explanation:
Use the Pythagorean theorem
a^2+b^2=c^2
6^2+7^2=c^2
36+49=c^2
85=c^2
c=9.21954446
round to what ever place you need
Your answer is two places to the right
Converting celsius to farenheit
C * 1.8 + 32
220 * 1.8 + 32 = 396 + 32 = 428 F....so 220 C = 428 F
so he set the oven for 428 F, when it was supposed to be set for 400 F
428 - 400 = 28.....28 degrees too hot
Y= - 5x + 7
Use the point and slope to solve for b, which is 7.