Answer:
7. x = 6
8. x = 9
9. x = 5
10. x = 10
Explanation:
7; from parallel lines and proportionality, we can say that;
(2x - 2)/20 = 6/12
Cross multiply to get;
2x - 2 = 20 × 6/12
2x - 2 = 10
2x = 10 + 2
2x = 12
x = 12/2
x = 6
8) on the left hand side, the total length there is 8. Thus, length of missing side is 8 - 3 = 5.
Thus,by proportion;
5/3 = 10/(x - 3)
Cross multiply to get;
5(x - 3) = 3 × 10
5x - 15 = 30
5x = 30 + 15
5x = 45
x = 45/5
x = 9
9) Similarly;
14/7x = 8/20
Cross multiply to get;
20 × 14 = 8 × 7x
280 = 56x
x = 280/56
x = 5
10) similarly;
14/(2x + 8) = 8/16
Cross multiply to get;
14 × 16 = 8(2x + 8)
Divide both sides by 8 to get;
14 × 16/8 = 2x + 8
2x + 8 = 28
2x = 28 - 8
2x = 20
x = 20/2
x = 10