Sterre charges \$35$35dollar sign, 35 to file tax returns, but files for free if she only needs the easiest form. then she donates \$2$2dollar sign, 2 to clean water projects per tax return she files. sterre charged \$7{,}245$7,245dollar sign, 7, comma, 245 and made a donation of \$1{,}242$1,242dollar sign, 1, comma, 242 this year for the tax returns she filed.

Let X = free tax returns

Y = $35 tax returns

Solve for Y:

0X + 35Y = 7245

35Y = 7245

Y = 7245 / 35

Y = 207 Tax Returns at $35

She donates $2 for every tax return

Now we can solve for X:

2(x+y) = 1242

2(x + 207) = 1242

2x + 414 = 1242

2x = 828

x = 828 / 2

x = 414 Free returns.

She did 414 returns for free and 207 returns for $35.

c-4 is the final answer! : )

quit

step-by-step explanation: