Answer:
x = -7 1/2
y = - 5/2
z = 11
Step-by-step explanation:
x— 3y+z= 6 (1)
2x — бу – 2 = -2 (2) <=> 2x - 6y = -2 + 2 = 0 <=> (2x - 6y)/2 = 0 <=> x - 3y = 0 (4)
—x+y+ 2 = 7 (3) <=> -x + y = 7 - 2 <=> x - y = -5 (5)
Subtract (5) from (4), we have:
(x - 3y) - (x - y ) = 0 - (-5)
<=> x - 3y - x + y = 5
<=> -2y = 5
<=> y = - 5/2
Replace y with (4), we have x = 3 × (-5/2) = -15/2 (or -7 1/2)
Replace x with -15/2 and y with -5/2 in (1), we have z = 6 - (-15/2 - (-5/2)) = 6 + (15/2 - 5/2) = 6 + 5 = 11
Answer:
14 girls
Step-by-step explanation:
boys : girls = total
5 : 7 = 12
10 : 14 = 24
