Answer:
i) x = 13
ii) x = -1
iii) x = 2
Explanation:
Given the following expressions, we are to find the corresponding value of x.
1) x-1 by 4=3
x-1/4=3
Cross multiply
x-1 = 4*3
x-1 = 12
x = 12+1
x = 13
2) Given 3x+6 by 2 = 3 by 2
3x+6/2=3/2
Cross multiply
2(3x+6) = 2(3)
2(3x) + 2(6) = 6
6x + 12 = 6
6x = 6-12
6x = -6
x = -6/6
x = -1
3) 3x-1by5=2x+3by7
This can also be written as:
(3x-1)/5 = (2x+3)/7
Cross multiply
7(3x-1) = 5(2x+3)
Open the bracket
7(3x) - 7(1) = 5(2x) + 5(3)
21x - 7 = 10x + 15
Collect like terms
21x - 10x = 15 + 7
11x = 22
x = 22/11
x = 2
