Question

find the solution of 5x+3y=12 and 15x+9y=15​

Answer 1

Step-by-step explanation:

5x+3y=12

substitute 3y in both places

5x+3y-3y=12-3y

5x=12-3y

now divide each side by 5

5x/5=12/5-3y/5

x=2.4+ -0.6y

Answer 2

5x+3y=12

5x=12-3y

X=12-3y/5

and in second equation

15x+9y=15

15(12-3y/5)+9y=15

180-75y/5+9y=15

taking LCM of 1 and 5

180-75y+45y/5=15

180-30y/5=15

taking 5 common

5(36-6y)/5 = 15

36-6y =15

36-15=6y

21=6y

3.5=y

since y=3.5

substituting value in equation one

5x+3(3.5)=12

5x+10.5=12

5x=12-10.5

5x=1.5

X=0.3