Courtney has a total of 88 stamps worth $15.56. Some are 25¢ stamps and some are 2¢ stamps. How many of each does she have?

88 stamps =  $15.56

A =number of  stamps=25 cent

B= number of  stamps =2 cent

A+B=88=A=88-B

0.25A+.02B=15.56

resolving

0.25(88-B)+0.02B=15.56

22-0.25B+0.02B=15.56

-0.23B=-6.44= B=28 stamps of 2 cent

A=88-B-- >88-28=60= A=60 stamps of 25 cent

step-by-step explanation:

∆abc has the points a(1, 7), b(-2, 2), and c(4, 2) as its vertices. formed with the point d(1, 2) as its third vertex, then ∆abd is triangle.