Question

practice: sec
write cross produ

1. $\frac{1}{10}=\frac{4}{40}$
2. $\frac{72}{81}=\frac{8}{9}$
3. $\frac{4}{15}=\frac{12}{45}$

Explanation:

Step1: Find cross product for #1

For $\frac{1}{10} = \frac{4}{40}$, cross multiply: $1 \times 40 = 10 \times 4$

Step2: Calculate cross product for #1

$1 \times 40 = 40$, $10 \times 4 = 40$

Step3: Find cross product for #5

For $\frac{72}{81} = \frac{8}{9}$, cross multiply: $72 \times 9 = 81 \times 8$

Step4: Calculate cross product for #5

$72 \times 9 = 648$, $81 \times 8 = 648$

Step5: Find cross product for #9

For $\frac{4}{15} = \frac{12}{45}$, cross multiply: $4 \times 45 = 15 \times 12$

Step6: Calculate cross product for #9

$4 \times 45 = 180$, $15 \times 12 = 180$

Answer:

1. $1 \times 40 = 10 \times 4$, $40=40$
2. $72 \times 9 = 81 \times 8$, $648=648$
3. $4 \times 45 = 15 \times 12$, $180=180$