Answer:
1. x = 4/5
2. y = 4
3. a = 2
Explanation:
first subtract the number without the variable from the answer. then divide the answer by whatever the number with the variable is.
1. 5x + 3 = 7
5x = 4
x = 4/5
2. 5.7 + 0.3y = 6.9
0.3y = 1.2
y = 4
3. 4.2 + 2.5a = 9.2
2.5a = 5
a =2