Question

The sum of 19 and 42 and a number is equal to 87. What is the number?

Answer 1

26

Explanation:

let x be a number.

19 + 42 + x = 87.

42 + x = 68.

x = 26.

Answer 2

`\huge\boxed{x=26}`

Write an equation.
`19+42+x=87`

Add.
`61+x=87`

Isolate
`x` by subtracting
`61` on both sides.
`\boxed{x=26}`