Question
If 2x + y = 10 and 3x - 2y = 5, find the value of x +
y.Solution
From the first equation, y = 10 - 2x. Substitute y = 10 - 2x into the second equation: 3x - 2(10 - 2x) = 5. 3x - 20 + 4x = 5. 7x = 25. x = 25/7. Substitute x = 25/7 into y = 10 - 2x: y = 10 - 2(25/7). y = 10 - 50/7. y = 70/7 - 50/7. y = 20/7. x + y = 25/7 + 20/7 = 45/7. Correct option: a
More Algebra Questions
- If n = 4 + √5, then find the value of (n + 1/n)².
- If [3a + (1/2a)] = 5, then find the value of [9a² + (1/4a²) - 6]
If n = 6 + √13, then find the value of (n + 1/n)².
If p3 + 9p2 + 8p + 13 = 6p2 + 5p + 12, then find the value of {(p4 + 1/p2)}/(p2 + 3p +...
If x, y and z are real numbers such that (x-5)2+(y-7)2+(z-9)2= 0 then (x+y+z) is equal to
If x4 + x - 4 = 47 then find the value of (x + x-1).
If (x + y) = 10 and xy = 21, then find the value of (x² + y²).
If x =7+4√3. then find the value of x +1/ x
