They made 3000$ in profit 500x100=50k
470x100=47k
47,000-50000=3000
A way to add fractions that always works is to multiply each numerator by the denominator of the other, then express the sum of products over the product of the denominators.

Here, you have
The sum is -1 1/12
D. he can access it by taking it out of his account
x = 4/5
2/5=1/2x
Step 1: Flip the equation.
1/2x=2/5
Step 2: Multiply both sides by 2.
2*(1/2x)=2*(2/5)x=4/5