Question

Help with maths homework please!

Answer 1

2)
3x + y =  9 is equivalent to -15x - 5y = -45 by multiplying both sides by -5

 -15x  - 5y = -45
+  4x + 5y =  23
 -11x + 0y = -22

-11x = -22
x = 2

3(2) + y = 9
6 + y = 9
y = 3

4)
2x + y = 17 is equivalent to -6x - 3y = -51 by multiplying both sides by -3

     4x + 3y =  37
+ (-6x  - 3y = -51)
   -2x + 0y = -14

-2x = -14
x = 7

4(7) + 3y = 37
28 + 3y = 37
3y = 9
y = 3

6)
x + 2y = 18 is equivalent to -10x - 20y = -180 by multiplying both sides by -10

     10x -   3y =   19
+ (-10x - 20y = -180)
      0x  - 23y = -161

-23y = -161
y = 7

10x - 3(7) = 19
10x - 21 = 19
10x = 40
x = 4

I hope this helped ^_^