If 40x represents a three-digit positive integer with a ones digit of x and 1x is a two-digit positive integer with a ones digit of x, what value of x makes the equation (40x)/(1x) = 31 true?
+128475 40x and be written as 4*10^2 + 0*10 + x = 400 + x
1x can be written as 1*10 + x = 10 + x
So we have
[ 400 + x ] / ;[ 10 + x ] = 31 multiply both sides by 10 + x
400 + x + 31 [ 10 + x ] simplify
400 + x = 310 + 31x
400 - 310 = 31x - x
90 = 30x diivide both sides by 30
x = 3
Check 403 / 13 = 31
