Question

The sum of three fourths of a number and 1 is -5

Answer 1

We need to give the mystery number an easy name so that we can work with it. Let's call it it ' M ' , for 'mystery number'.The number . . . . . . . . . . . . . M3/4 of it . . . . . . . . . . . . . . . . . 3/4 Mthe sum of 3/4 of it and 1 . . . (3/4 M + 1)You said that sum is equal to -5 .OK. The equation we need to solve is 3/4 M + 1 = - 5Subtract 1 from each side: 3/4 M = - 6Multiply each side by 4 : 3 M = -24Divide each side by 3 : M = - 8Does it work ?Check it :-- Assume the mystery number is . . . -8 .-- 3/4 of the number . . . . . . . . . . . . . - 6 .-- sum of 3/4 of the number and 1 . . . -5 <== yay !

Explanation:

Answer 2

We need to give the mystery number an easy name so that
we can work with it. Let's call it it ' M ' , for 'mystery number'.

The number . . . . . . . . . . . . . M
3/4 of it . . . . . . . . . . . . . . . . . 3/4 M
the sum of 3/4 of it and 1 . . . (3/4 M + 1)

You said that sum is equal to -5 .
OK. The equation we need to solve is

3/4 M + 1 = - 5

Subtract 1 from each side: 3/4 M = - 6

Multiply each side by 4 : 3 M = -24

Divide each side by 3 : M = - 8


Does it work ?

Check it :

-- Assume the mystery number is . . . -8 .
-- 3/4 of the number . . . . . . . . . . . . . - 6 .
-- sum of 3/4 of the number and 1 . . . -5 <== yay !