We are given that y = 4, and we need to find the value of each expression by substituting 4 in place of y.
Let’s go one by one:
1.
21 - y
Substitute y = 4:
21 - 4 = 17
2.
y + 25
Substitute y = 4:
4 + 25 = 29
3.
3y + 2
First, 3 × 4 = 12, then add 2:
12 + 2 = 14
4.
3y
3 × 4 = 12
5.
y / 2
4 ÷ 2 = 2
6.
y / 16
4 ÷ 16 = 0.25 (or 1/4)
7.
(2y - 5) / 4
First, 2 × 4 = 8
Then, 8 - 5 = 3
Then, 3 ÷ 4 = 0.75 (or 3/4)
8.
y² + 4
y² means y × y → 4 × 4 = 16
Then, 16 + 4 = 20
9.
2y²
First, y² = 4 × 4 = 16
Then, 2 × 16 = 32
10.
y³ - 20
y³ means y × y × y → 4 × 4 × 4 = 64
Then, 64 - 20 = 44
All calculations checked.
Final Answer:
17, 29, 14, 12, 2, 0.25, 0.75, 20, 32, 44
Parent Tip: Review the logic above to help your child master the concept of math expressions grade 5 worksheet.
