Which equation can be used to solve for x, the increase in side length of the square in inches? x2 + 4x – 81 = 0 x2 + 4x –

Question

Which equation can be used to solve for x, the increase in side length of the square in inches?

x2 + 4x – 81 = 0
x2 + 4x – 65 = 0
x2 + 8x – 65 = 0
x2 + 8x – 81 = 0

in progress 0
Farah 3 years 2021-07-30T23:29:16+00:00 2 Answers 53 views 0

Answers ( )

  1. King
    0
    2021-07-30T23:30:41+00:00
    Reply

    Answer:

    x2 + 8x – 65 = 0

    Step-by-step explanation:

    Complete question

    A square picture with a side length of 4 inches needs to be enlarged. The final area needs to be 81 square inches. Which equation can be used to solve for x, the increase in side length of the square in inches? x2 + 4x – 81 = 0 x2 + 4x – 65 = 0 x2 + 8x – 65 = 0 x2 + 8x – 81 = 0

    Given the initial side length = 4in

    Initial area = L²

    L is side length of the square

    Initial area = 4²

    Initial area = 16 square inches

    Area of the enlarged square = 81 square inches

    To get the constant term of the expression, we will find the difference in the areas

    Difference = 85 – 16

    Difference = 65 square units

    The coefficient of x will be the 2 *initial area of the square

    Given the standard form of an expression as

    ax^2 + bx + c

    a = 1, b = 2*4 = 8, c = -65

    Substitute

    x^2 + 8x – 65

    This gives the required expression

  2. thugiang
    0
    2021-07-30T23:30:48+00:00
    Reply

    Answer:

    C) x2 + 8x – 65 = 0

    Step-by-step explanation:

    edge

Leave an answer

Browse

Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )