Q. If 7x−8y=−10 and 10x+4y=6 are true equations, what would be the value of 17x−4y ?Answer:
Equations Setup: We have two equations:1) 7x−8y=−102) 10x+4y=6We need to find the value of 17x−4y. To do this, we can use the method of elimination or substitution. Let's use elimination by multiplying the second equation by 2 to make the coefficient of y in both equations the same.
Multiply Second Equation: Multiply the second equation by 2: 2×(10x+4y)=2×6This gives us: 20x+8y=12Now we have a new set of equations: 1) 7x−8y=−102) 20x+8y=12
Add Equations: We can now add the two equations together to eliminate y:(7x−8y)+(20x+8y)=−10+12This simplifies to:7x+20x=2
Solve for x: Combine like terms:27x=2Now we need to solve for x:x=272
Substitute x into Equation: Now that we have the value of x, we can substitute it back into one of the original equations to find the value of y. Let's use the first equation:7x−8y=−10Substitute x=272 into the equation:7×(272)−8y=−10
Isolate y Term: Simplify the equation:2714−8y=−10To solve for y, we need to isolate the y term. Let's move 2714 to the other side of the equation:−8y=−10−2714
Divide by −8: To combine the terms on the right side, we need a common denominator. The common denominator for 10 and 2714 is 27:\(-8y = \left(-\frac{270}{27}\right) - \left(\frac{14}{27}\right)
Find y Value: Combine the terms on the right side:−8y=−27284Now, divide both sides by −8 to solve for y:y=−8−27284
Substitute x and y: Simplify the division:y=(27×8)284y=216284y=5471
Simplify Expression: Now we have the values of x and y. We can find the value of 17x−4y by substituting these values into the expression:17x−4y=17×(272)−4×(5471)
Simplify Expression: Now we have the values of x and y. We can find the value of 17x−4y by substituting these values into the expression:17x−4y=17×(272)−4×(5471)Simplify the expression:17x−4y=(2734)−(4×5471)To subtract these fractions, we need a common denominator. The common denominator for 27 and 54 is 54:17x−4y=(5434×2)−(4×5471)
Simplify Expression: Now we have the values of x and y. We can find the value of 17x−4y by substituting these values into the expression:17x−4y=17×(272)−4×(5471)Simplify the expression:17x−4y=(2734)−(4×5471)To subtract these fractions, we need a common denominator. The common denominator for 27 and 54 is 54:17x−4y=(5434×2)−(4×5471)Combine the terms:17x−4y=(5468)−(54284)17x−4y=5468−284
Simplify Expression: Now we have the values of x and y. We can find the value of 17x−4y by substituting these values into the expression:17x−4y=17×(272)−4×(5471) Simplify the expression:17x−4y=(2734)−(4×5471)To subtract these fractions, we need a common denominator. The common denominator for 27 and 54 is 54:17x−4y=(5434×2)−(4×5471) Combine the terms:17x−4y=(5468)−(54284)y0 Subtract the numerators:y1Simplify the fraction:y2
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