ЁЯУв Too many exams? DonтАЩt know which one suits you best? Book Your Free Expert ЁЯСЙ call Now!

    Question

    Find the value of 'a' and 'b' which satisfy the

    following equations: 9a + 7b = 30 4a - 5b = 62
    A a = 6 and b = - 8 Correct Answer Incorrect Answer
    B = - 8 and b = 6 a Correct Answer Incorrect Answer
    C a = 8 and b = - 6 Correct Answer Incorrect Answer
    D a = - 6 and b = 8 Correct Answer Incorrect Answer

    Solution

    9a + 7b = 30 ---------- (I) 4a - 5b = 62 ---------- (II) On solving 5 X equation I + 7 X equation II, We get, 5 X (9a + 7b) + 7 X (4a - 5b) = 5 X 30 + 7 X 62 Or, 45a + 35b + 28a - 35b = 150 + 434 Or, 73a = 584 Or, 'a' = 8 On putting value of 'a' in equation I, We get, 9 X 8 + 7b = 30 Or, 72 + 7b = 30 Or, 7b = - 42 Or, 'b' = - 6

    Practice Next
    More Linear Equation Questions

    Relevant for Exams:

    ask-question