Question

Twice one number added to three times another gives 21 Find the number if the difference between them is 3​

Answer 1

Answer:

2x+3y=21

x-y=3

Lets use substitution;

first change the second equation so you have what x equals;

x=3+y

Now plug that into the first equation for x;

2(3+y)+3y=21

6+2y+3y=21

5y=21-6

5y=15

y=3

Now plug your y value into the second equaiton;

x-3=3

x=3+3

x=6

check;

6-3=3

2(6)+3(3)=21

12+9=21.