Home › UP Board Class 10 › mathematics › linear_equations › Solve by substitution: x + y = 10, x − y = 4.
Solve by substitution: x + y = 10, x − y = 4.
A(7, 3)
B(3, 7)
C(5, 5)
D(4, 6)
Answer & Solution
Correct answer: A. (7, 3)
Add the two equations: 2x = 14 ⇒ x = 7, then y = 10 − 7 = 3.
Related questions
A two-digit number has digits whose sum is 9. Reversing the digits decreases the number byFive years ago A was thrice as old as B. Ten years later A will be twice as old as B. FindSolve 1/x + 1/y = 1/3 and 1/x − 1/y = 1/12.A boat travels 30 km downstream and 18 km upstream in 4 hours. It also travels 40 km downsA father is 30 years older than his son. After 5 years the father will be three times as oThe sum of two numbers is 25 and their difference is 5. Find them.A pair of equations gives a single solution iff:Solve 4x + 3y = 11 and 3x − 4y = 2.