This page 10th cbse maths solution for exercise 3.4 is going to provide you solution for every problems that you find in the exercise no 3.4
(1) Solve the following pairs of linear equations by the elimination method and the substitution method
(i) x + y = 5 and 2 x – 3 y = 4 Solution
(ii) 3 x + 4 y = 10 and 2 x – 2 y = 2 Solution
(iii) 3 x – 5 y – 4 = 0 and 9 x = 2 y + 7 Solution
(iv) (x/2) + (2y/3) = -1 and x – (y/3) = 3 Solution
(2) Form the pair of linear equations in the following problems, and find their solutions (if they exists) by the elimination method:
(i) If we add 1 to the numerator and subtract 1 from the denominator, a fraction reduces to 1, it becomes ½ if we only add 1 to the denominator. What is the fraction? Solution
(ii) Five years ago, Nuri was thrice as old as sonu. Ten years later, Nuri will be twice as old as Sonu. How old are Nuri and Sonu? Solution
(iii) The sum of the digits of two digit number is 9. Also nine times this number is twice the number obtained by reversing the order of the digits. Find the number.
(iv) Meena went to bank to withdraw Rs.2500.She asked the cashier to give her Rs.50 and Rs.100 notes only. Meena got 25 notes in all. Find how many notes of Rs.50 and Rs.100 she received.
(v) A lending library has a fixed charge for the first three days and an addition charge for each day thereafter. Saritha paid Rs.27 for a book kept for seven days. While Susy paid Rs.21 for the book she kept for five days. Find the fixed charge and the charge for each extra day.