Question

i thought of a number. four times the number increased by 30 equals 70 decreased by the number. what was my number?

Answer 1

number is 8

Explanation:

let n be the number then 4 times the number is 4n and increased by 30 means adding 30 to it , that is 4n + 30

70 decreased by the number means subtracting n fro 70 , 70 - n

then

4n + 30 = 70 - n ( add n to both sides )

5n + 30 = 70 ( subtract 30 from both sides )

5n = 40 ( divide both sides by 5 )

n = 8