Question

the sum of two number is 9 and 3 times of one of them is less than 4 times the second by 1 find the largest number

Answer 1

let one be x and other be y
then according to question
x+y=9 ---------------------eq- 1
4x-3y=1 --------------------eq-2
in order to solve these equations we multiply equation 1 by 3 in order to eliminate variable y
3(x+y=9)
3x+3y=27 -----------------eq-3
add equation 2 and3
4x-3y=1
3x+3y=27
then
7x=28
x=4
put the value of x in eq 1
y=5
so the larger no is 5