5x+7y= -1
-3x+4y= -24

x = 4

y = -3

Step-by-step explanation:

multiply top equation by 3

multiply bottom equation by 5

cancel terms that can be cancelled (15x and -15x) add the others

15x + 21y = -3

-15x + 20y = -120

41y = -123

y = -123/41= -3

plug y = -3 into the top equation

5x - 21 = -1

5x = 20

x = 4

simultaneous equations:

if we want to cancel out y, multiply the bottom equation by 1.75

to get  -5.25x + 7y= -42

  5x+ 7y = -1

--5.25x + 7y = -42

= 10.25x = 41

x=41/10.25

x=4

substitute to find y

5*4

20+7y=-1

7y=-21

y=-3

other equation:

-3*4 + 4*-3

-12+-12=-24

-12-12=24

v = 1/3 a^2h

step-by-step explanation:

the volume is 1/3 a^2h.