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Solve: 4x + 3y = 18 and 2x - y = 4. What is the value of x?
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Substitute the given options directly into the equations to quickly check which value of x satisfies both equations simultaneously.
Given linear equations are 4x+3y=18 and 2xтИТy=4.
y=24xтИТ4тАЛ
Substitute the given options directly into the equations to quickly check which value of x satisfies both equations simultaneously.
Multiplying only one term of the equation when trying to equate coefficients during elimination, leading to incorrect values of x and y.
Write down the given equations
We have two equations: Equation (1) is 4x+3y=18 and Equation (2) is 2xтИТy=4.
4x+3y=18,2xтИТy=4
Eliminate y by equating coefficients
Multiply Equation (2) by 3 so that the coefficients of y in both equations become opposites (3y and тИТ3y).
3(2xтИТy)=3(4)тЯ╣6xтИТ3y=12
Add the equations
Add the modified Equation (2) to Equation (1) to eliminate y: (4x+3y)+(6xтИТ3y)=18+12.
10x=30
Solve for x
Divide both sides by 10 to find the value of x: x=1030тАЛ.
x=3
B is correct because solving the simultaneous linear equations yields x=3 and y=2.
Simultaneous equations frequently appear in quantitative aptitude and reasoning sections; mastering both elimination and substitution saves valuable exam time.