125 minutes, or 2 hours and 5 minutes.
cross multiply
5*175=7x
875=7x
125=x
Two of anything plus another one of the same thing always results in a total of 3 of them. It doesn't matter whether the things are cows, mushrooms, ideas, or rocks. In this question they happen to be ninths.
Simplifying
(6x + -5) + -1(7x + 2) = 0
Reorder the terms:
(-5 + 6x) + -1(7x + 2) = 0
Remove parenthesis around (-5 + 6x)
-5 + 6x + -1(7x + 2) = 0
Reorder the terms:
-5 + 6x + -1(2 + 7x) = 0
-5 + 6x + (2 * -1 + 7x * -1) = 0
-5 + 6x + (-2 + -7x) = 0
Reorder the terms:
-5 + -2 + 6x + -7x = 0
Combine like terms: -5 + -2 = -7
-7 + 6x + -7x = 0
Combine like terms: 6x + -7x = -1x
-7 + -1x = 0
Solving
-7 + -1x = 0
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '7' to each side of the equation.
-7 + 7 + -1x = 0 + 7
Combine like terms: -7 + 7 = 0
0 + -1x = 0 + 7
-1x = 0 + 7
Combine like terms: 0 + 7 = 7
-1x = 7
Divide each side by '-1'.
x = -7
Simplifying
x = -7
