Q. If −6x−9y=6 and −4x+y=−1 are true equations, what would be the value of −10x−8y ?Answer:
Identify Equations: Identify the system of equations.We have two equations:1) −6x−9y=62) −4x+y=−1We need to find the value of −10x−8y.
Solve for y: Solve the second equation for y.From equation 2) −4x+y=−1, we can express y in terms of x:y=−1+4x
Substitute in Equation 1: Substitute the expression for y into the first equation.Replace y in equation 1) with the expression from the previous step:−6x−9(−1+4x)=6
Distribute and Simplify: Distribute and simplify the first equation.−6x+9−36x=6Combine like terms:−42x+9=6
Solve for x: Solve for x.Subtract 9 from both sides:−42x=−3Divide by −42:x=−3/−42x=1/14
Substitute x into y: Substitute the value of x back into the expression for y. y=−1+4(141) y=−1+144 y=−1+72 y=−77+72 y=−75
Calculate −10x−8y: Calculate the value of −10x−8y using the found values of x and y.−10x−8y=−10(141)−8(−75)=−1410+740
Simplify Expression: Simplify the expression.First, simplify −1410:−1410=−75Now, add −75 to 740:−75+740=735