7 cm: 35000 cm (7*5000)
2.8 cm: 14000 cm (2.8*5000)
2 cm: 10000 cm (2*5000)
Okay so the zero property of multiplication is anything times zero equals zero, so just use a number, multiply it times zero, and show what it equals (which is zero) explain that it shows the property because the variable is multiplied times zero.
C.) 30 since they both have 5's just take them out then subtract 50 and 20 *but make sure u take out the decimal though* so after u subtract u will get 30 then line it up and put the decimal back then it will be .30
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
