Answer:
13) 10
17) 15
21) 10
25) 1
Step-by-step explanation:
13)
5x becomes 5(2) which is 5 times 2 = 10
17)
(4x) + 7 becomes (4 times 2) + 7 = 15
21)
(2x) + (2y) becomes (2 times 2) + (2 times 3)
= 4 + 6
= 10
25)
1/2(z - x) becomes 1/2(4 - 2)
= 1/2(2)
= 1
