Question 3. Solve the following pair of linear equations by the substitution and cross-m Chapter 3: Pair of Linear Equations in Two Variable Maths Class 10 solutions are developed for assisting understudies with working on their score and increase knowledge of the subjects. Question 3. Solve the following pair of linear equations by the substitution and cross-multiplication methods: 8x +5y =9 …(1) 3x +2y =4 …(2) is solved by our expert teachers. You can get ncert solutions and notes for class 10 chapter 3 absolutely free. NCERT Solutions for class 10 Maths Chapter 3: Pair of Linear Equations in Two Variable is very essencial for getting good marks in CBSE Board examinations
Question 3. Solve the following pair of linear equations by the substitution and cross-multiplication methods:
8x +5y =9 …(1)
3x +2y =4 …(2)
Solution: Substitution method :-
8x +5y =9
Subtract 8x both sides we get
5y = 9 – 8x
Divide by 5
Y = (9 – 8 x)/5 …(3)
Plug this value of y in equation second we get
3x +2y =4
3x + 2(9 – 8 x)/5) = 4
Multiply by 5 we get
15 x + 18 - 16 x = 20
-x = 2
X = - 2
Plug this value back in equation (3) we get
Y = (9- 8(-2))/5
Y = 25/5
Y = 5
Answer is x = -2 and y = 5
Cross multiplication method
8x +5y =9 …(1)
Subtract 9 both side we get
8x +5y – 9 = 0
3x +2y =4 …(2)
Subtract 4 both side we get
3x + 2y – 4 = 0
Compare with
we get
a1 = 8 , b1 = 5 , and c1 = -9
a2 = 3 , b2 = 2 and c2 = -4
Use the formula of cross multiplication
We get x = -2 and y = 5
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