jamal bought donuts and cupcakes. he bought three times as many donuts as cupcakes. cupcakes cost .50 cent each and donuts cost a $1.00 each. jamaal spent $10.00 total. how many cupcakes did he buy? how many donuts did he buy?

He bought 4 cupcakes and 12 donuts

Step-by-step explanation:

He bought three times as many donuts as cupcakes so we could represent that by the equation  d= 3c  where d is donuts and c is the cupcakes.

If cupcakes also cost 50 cent and donuts cost a dollar each and he spent a total of 10 dollars then we could also represent that by the equation  

0.50d + 1c = 10    

Now combine use the two equations and solve for d and c

d= 3c

0.50d + 1c =10    substitute d in the first equation into the second equation.

0.50(3c) + 1c =10

1.5c + 1c =10

2.5c = 10

  c=  4  

In this case he bought a total of 4 cupcakes and to find the total of donuts that he bought we multiply that by 3 because he bought three times as much as that.

d= 3 * 4

d = 12

step-by-step explanation:

b and c

the answer is y < -3 or   y > 3

-3y > 7 + 2

-3 y > 9

y < -3