Question

Please help me to solve this problem 3x-y=9,2x+3y=17

Answer 1

Question

Solve this problem 3x-y=9 , 2x+3y=17

Solution

Substitution method :-

Given equation

• 3x - y = 9 .........equ(1).
• 2x + 3y = 17 .......equ(2).

By, equ(1),

• y = 3x - 9 .........equ(3).

Substitute value of y in equ(2),

➠ 2x + 3(3x-9) = 17

➠2x + 9x - 27 = 17

➠ 11x = 27 + 17

➠ 11x = 44

➠x = 44/11

➠ x = 4

Keep value of x in equ(3)

➠ y = 3×4 - 9

➠y = 12 -9

➠ y = 3

Hence:-

• value of x = 4
• Value of y = 3

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Elimination method

Equation given,

• 3x - y = 9 ..........(4)
• 2x + 3y = 17 ........(5)

multiply by 2 in equ(4) and 3 in equ(5)

• 6x - 2y = 18
• 6x + 9y = 51

____________Sub. it's (eliminate x)

➠ ( -2y - 9y) = (18 - 51)

➠ -11y = - 33

➠y = (-33)/(-11)

➠ y = 3

keep value of y in equ(4),

➠ 3x - 3 = 9

➠ 3x = 9 + 3

➠ 3x = 12

➠ x = 12/3

➠ x = 4

Hence:-

• value of x = 4
• Value of y = 3

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