Answer:
x = 72 / 85
Step-by-step explanation:
x -6/7=-x/84
x + x/84 = 6/7
84/84x + 1/84x = (12*6) / (12*7)
85/84x = ( 72 ) / ( 84 )
85/84x = 72 / 84
Multiply left and right from the = sign by 84/85 and you do that so you get a division ON THE LEFT SIDE that equals as 1... See how it works:
84/85 * { 85/84 } * x = 84/85 * { ( 72 ) / ( 84 ) }
{ (84 * 85) / ( 85 * 84) } * x = ( 84 * 72 ) / ( 85 * 84 )
(7140) / ( 7140) * x =. ( 6048 ) / ( 7140)
x = 6048 / 7140
x = 72 / 85
Answer: Infinite solutions.
Step-by-step explanation:

Plug the value of y into the second equation.

Add 12 on both sides.

Add 4x on both sides.


Answer:
2 per minute
Step-by-step explanation:
Because 8 divided by 4 is 2.
Answer:Yes
Step-by-step explanation:You are multiplying the ratios by 4
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
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