Question 165460
FIRST OF ALL, WE NEED TO KNOW HOW MUCH WHITE PAINT THAT YOU HAVE TO START WITH. SINCE WE DON'T KNOW, WE'LL LET "A" REPRESENT THE AMOUNT OF WHITE PAINT AND YOU CAN ADD IN THE ACTUAL VALUE.

Let A=amount of white paint the you have to start with
And let x=amount of 7% paint that is added

Now we know that the amount of pure color in the 7% paint that is added(0.07x) plus the amount of pure color in the white paint(0) has to equal the amount of pure color in the final mixture (0.03(A+x)), so our equation to solve is:
0.07x=0.03(A+x)  get rid of parens (distributive law)
0.07x=0.03A+0.03x  subtract 0.03x from each side
0.07x-0.03x=0.03A+0.03x-0.03x  collect like terms
0.04x=0.03A  divide each side by 0.04
x=0.75A

CK
0.07*0.75A=0.03(A+0.75A)
0.525A=0.03*1.75A
0.525A=0.525A


Hope this helps---ptaylor