13.3 repeating all you have to do is convert them into seconds and divide them by nine
100cm is equivalent to 1m so 500cm is equivalent to 5m. What you need to do is divide 500cm (5metres) by 25cm (one quarter of a metre). So the number sentence using 'division' should look like 500cm divided by 25cm which equals 20. Don't forget to use proper symbols for division though. Let me know if this helps:)
Answer:
(6 , -1)
Step-by-step explanation:
2x+ y = 11 ----------------(I)
y = 11 - 2x --------------------(II)

Multiply the whole equation by 2

x - 10y = 16 --------------------(III)
Substitute y = 11- 2x in equation (III)
x - 10(11 - 2x) = 16
x - 110 + 20x = 16
21x - 110 = 16
21x = 16 +110
21x = 126
x = 126/21
x = 6
Plugin x = 6 in equation (II)
y = 11 - 2*6
y = 11 - 12
y = -1