Answer:
f(x) = -60 is your answer
Step-by-step explanation:
Plug in 3 for x
f(x) = 5x² - 7(4x + 3)
f(x) = 5(3²) - 7(4(3) + 3)
Follow PEMDAS. First, solve the parenthesis
3² = 9
4(3) + 3 = 12 + 3 = 15
f(x) = 5(9) - 7(15)
Multiply
f(x) = 45 - 105
Simplify. Subtract
f(x) = 45 - 105
f(x) = -60
f(x) = -60 is your answer
~
A repeating decimal (rational ends, irrational doesnt)
Answer:
6.) -3.544
Step-by-step explanation:
6.2(x+3.5)-x =6.2x+21.7 -x =6.2x-x+21.7 =5.2x+21.7
-3(6-2x) =-18(+-)6x =-18-6x
5.2x +6x=-18-21.7
11.2x=-39.7
x=-39.7÷11.2
x=3.544
30(30 – x) = 540
distribute
900 -30x = 540
subtract 900 from each side
-30x = -360
divide by -30
x =12