I tried many times to solve the following 2 problems but cannot get the answer. It looks simple enough yet so tough.

Solve each system of equation by substitution.

Problem 1.

2c - d + 2 = 0

3c + 2d + 10 = 0

Problem 2.

a + 4b = 3

5b = -2a + 3

No matter how I substitute, my answers could not match the answer key. The answer key for problem 1 is (-2,-2) and problem 2 is (-1,1). Please help. Thanks.