Given:
(a) A / B = 7/20
(b) A + B = 135
Let A = B * 7/20
Sub A = B * 7 into (b)
(B * 7/20) + B = 135
B * 27/20) = 135
B = 135/(27/20)
B = 100
Sub B = 100 into (a)
A / (100) = 7/20
A = 7/20 * 100
A = 35
Therefore, A equals 35 and B equals 100.
Check
LS
35/100 = 0.35
RS
7/20 = 0.35
(a) A / B = 7/20
(b) A + B = 135
Let A = B * 7/20
Sub A = B * 7 into (b)
(B * 7/20) + B = 135
B * 27/20) = 135
B = 135/(27/20)
B = 100
Sub B = 100 into (a)
A / (100) = 7/20
A = 7/20 * 100
A = 35
Therefore, A equals 35 and B equals 100.
Check
LS
35/100 = 0.35
RS
7/20 = 0.35