Question

x-7y=-42, x-3y=6 Solve using substitution method.​

Answer 1

Answer:

$x - 7y = - 42 (1) \\ x - 3y = 6(2) \\ \\ make \: x \: subject \: from \: eq(1) \\ \\ x = - 42 + 7y \: (3) \\ put \: eq(3) \: in \: eq (2) \\ q \\ we \: get \\ - 42 + 7y - 3y = 6 \\ - 42 + 4y = 6 \\ 4y = 6 + 42 \\ 4y = 48 \\ y = 48 \div 4 \\ y = 12 \\ \\ \\ \\ now \: \\ from \: eq \: (3) \\ x = - 42 + 7y \\ x = - 42 + 7 \times 12 \\ x = - 42 + 84 \\ x = 42 \\ hence \: x = 42 \: and \: y = 12 \\ by \: lokesh \: sir$

Step-by-step explanation:

−42+7y−3y=6

−42+4y=6

4y=6+42

4y=48

y=48÷4

y=12

now

fromeq(3)

x=−42+7y

x=−42+7×12

x=−42+84

x=42

hencex=42andy=12

bylokeshsir