Solve by factoring
x squared-30=7x

X²-30=7x
x²-7x-30=0
something times something = -30
something + something  -7
(x+3) (x-10)=0
x= -3 and 10

X^2-30=7x

we will try to get it eqpal to zero
subtract 7x form both sdies
x^2-7x-30=0
factor because is xy=0 then x and/or y=0

so
find what 2 numbers add to -7 and multiply to -30
the numbers are -10 and 3

(x-10)(x+3)=0
so set them to zero
x-10=0
add 10
x=10

x+3=0
sbtract 3
x=-3

x=10 or -3

M< 5 = 80 , < 2 = 80, < 6= 100, < 3= 100, < 7= 80, < 4= 80, < 8= 100