-13=78+b

Rewrite the equation as 78+b=-13.

78+b=-13

Move the negative in front of the fraction.

78+b=-13

Subtract 78 from both sides of the equation.

b=-13-78

To write -13 as a fraction with a common denominator, multiply by 88.

b=-13⋅88-78

To write -78 as a fraction with a common denominator, multiply by 33.

b=-13⋅88-78⋅33

Write each expression with a common denominator of 24, by multiplying each by an appropriate factor of 1.

Multiply 13 and 88.

b=-83⋅8-78⋅33

Multiply 3 by 8.

b=-824-78⋅33

Multiply 78 and 33.

b=-824-7⋅38⋅3

Multiply 8 by 3.

b=-824-7⋅324

b=-824-7⋅324

Combine the numerators over the common denominator.

b=-8-7⋅324

Simplify the numerator.

Multiply -7 by 3.

b=-8-2124

Subtract 21 from -8.

b=-2924

b=-2924

Move the negative in front of the fraction.

b=-2924

b=-2924

The result can be shown in multiple forms.

Exact Form:

b=-2924

Decimal Form:

b=-1.2083‾

Mixed Number Form:

b=-1524

Solve for b -1/3=7/8+b