You need to tell how many percent you will discount and then find the new price
4x - 2y - z = - 5 ______×2x - 3y + 2z = 3 _______×13x + y - 2z = - 5 ______×1
8x - 4y - 2z = - 10x - 3y + 2z = 33x + y - 2z = - 5
8x - 4y - 2z = - 10(+) x - 3y + 2z = 3_____________9x - 7y = - 77y = 9x + 7y = 9/7x + 1
x - 3y + 2z = 3(+) 3x + y - 2z = - 5_____________4x - 2y = - 24x - 2(9/7x + 1) = - 24x - 18/7x - 2 = - 210/7x = 0x = 0
y = 9/7(0) + 1y = 1
0 - 3(1) + 2z = 32z = 6z = 3
Answer:
40⁰ is angle boc
Aod is 75⁰ hope it's help yo