Question

(7)

x	8	40	56	72
y	2	10	14	18

(8)

x	7	__	__	63
y	2	6	12	__

(9)

x	10	__	15	18
y	__	80	__	72

(10)

x	6	20	__	10
y	__	60	42	__

(11)

x	3	10	4	5
y	12	__	__	__

(12)

x	6	12	18	24
y	4	__	__	__

Explanation:

Problem 7

Step1: Find the relationship between x and y.

From the first pair (8, 2), we see that \( 8 \div 4 = 2 \), so the relationship is \( y=\frac{x}{4} \) or \( x = 4y \).

Step2: Calculate the missing x when y = 10.

Using \( x = 4y \), substitute y = 10: \( x = 4\times10 = 40 \).

Step3: Calculate the missing y when x = 56.

Using \( y=\frac{x}{4} \), substitute x = 56: \( y=\frac{56}{4}=14 \).

Step4: Calculate the missing y when x = 72.

Using \( y=\frac{x}{4} \), substitute x = 72: \( y=\frac{72}{4}=18 \).

Step1: Find the relationship between x and y.

From the first pair (7, 2), let's check the ratio. Wait, maybe another relationship. Let's see the differences or multiples. Wait, 7 to 2: maybe \( x=\frac{7}{2}y \)? Let's check. When y = 2, x = 7. When y = 6, \( x=\frac{7}{2}\times6 = 21 \). When y = 12, \( x=\frac{7}{2}\times12 = 42 \). When x = 63, \( y=\frac{2}{7}\times63 = 18 \). Let's verify:

• For y = 6: \( x=\frac{7}{2}\times6 = 21 \)
• For y = 12: \( x=\frac{7}{2}\times12 = 42 \)
• For x = 63: \( y=\frac{2}{7}\times63 = 18 \)

Yes, the relationship is \( x=\frac{7}{2}y \) or \( y=\frac{2}{7}x \).

Step2: Calculate x when y = 6.

\( x=\frac{7}{2}\times6 = 21 \)

Step3: Calculate x when y = 12.

\( x=\frac{7}{2}\times12 = 42 \)

Step4: Calculate y when x = 63.

\( y=\frac{2}{7}\times63 = 18 \)

Step1: Find the relationship between x and y.

From the last pair (18, 72), \( 72\div18 = 4 \), so the relationship is \( y = 4x \) or \( x=\frac{y}{4} \).

Step2: Calculate y when x = 10.

Using \( y = 4x \), substitute x = 10: \( y = 4\times10 = 40 \)

Step3: Calculate x when y = 80.

Using \( x=\frac{y}{4} \), substitute y = 80: \( x=\frac{80}{4}=20 \)

Step4: Calculate y when x = 15.

Using \( y = 4x \), substitute x = 15: \( y = 4\times15 = 60 \)

Answer:

x: 40; y: 14, 18

Problem 8