If A = 3x² - 4x + 1, B = 5x² + 3x - 8 and C = 4x² - 7x + 3, then find B + C - A

Solution:

Given, A = 3x² - 4x + 1, B = 5x² + 3x - 8 and C = 4x² - 7x + 3

We have to find B + C - A

C - A = 4x² - 7x + 3 - (3x² - 4x + 1)

= 4x² - 7x + 3 - 3x² + 4x - 1

By combining like terms,

= 4x² - 3x² - 7x + 4x + 3 - 1

= (4 - 3)x² + (-7 + 4)x + (3 - 1)

= (1)x² + (-3)x + 2

C - A = x² - 3x + 2

Now, B + C - A = 5x² + 3x - 8 + (x² - 3x + 2)

= 5x² + 3x - 8 + x² - 3x + 2

By combining like terms,

= 5x² + x² + 3x - 3x - 8 + 2

= (5 + 1)x² + (3 - 3)x + (-8 + 2)

= (6)x² + (0)x + (-6)

Therefore, B + C - A = 6x² - 6

✦ Try This: If A = x² + x + 1, B = 4x² - 3x + 2 and C = x² - 4x + 6, then find B + C - A

☛ Also Check: NCERT Solutions for Class 7 Maths Chapter 12

NCERT Exemplar Class 7 Maths Chapter 10 Problem 68 (ii)

If A = 3x² - 4x + 1, B = 5x² + 3x - 8 and C = 4x² - 7x + 3, then find B + C - A

Summary:

If A = 3x² - 4x + 1, B = 5x² + 3x - 8 and C = 4x² - 7x + 3, then B + C - A is 6x² - 6

☛ Related Questions:

• If A = 3x² - 4x + 1, B = 5x² + 3x - 8 and C = 4x² - 7x + 3, then find A + B + C
• If P = -(x - 2), Q = -2(y +1) and R = -x + 2y, find a, when P + Q + R = ax
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