Question

If 4r+7s=23 and r−2s=17 then 3r+3s=

Answer 1

Answer:24

Explanation:

4r+7s=23..............(1)

r-2s=17................(11)

From (11) r=17+2s

Substitute r=17+2s in 4r+7s=23

4(17+2s)+7s=23

Open brackets

68+8s+7s=23

68+15s=23

15s=23-68

15s=-45

Divide both sides by 15

15s/15=-45/15

s=-3

substitute s=-3 in r-2s=17

r-2(-3)=17

r+6=17

r=11

3r + 3s=3(11)+3(-3)

33-9=24

Answer 2

24

Explanation:

4r+7s=23

r-2s=17

If you add the two equations together, you are left with:

5r+5s=40

If you divide both sides of the equation by 5, you get:

r+s=8

Now, if you multiply both sides by 3, you get:

3r+3s=24

Hope this helps!