There is a rectangle, which is 2cm wide and 3cm long, and its area is 120cm square. Q: what's the area of the original rectangle? Fast Give me the formula

There is a rectangle, which is 2cm wide and 3cm long, and its area is 120cm square. Q: what's the area of the original rectangle? Fast Give me the formula

Let the length be a and the width be B
(a+3)×(b+2)=ab+120
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The length of a rectangle is 2xcm, and the width is 4cm less than the length. If the length and width of the rectangle are increased by 3cm, how much is the area increased? X = 4m, how much is the area increased?

Area increase
（2x+3）(2x-4+3)-2x(2x-4)
=（2x+3）(2x-1)-4x²+8x
=4x²+4x-3-4x²+8x
=12x-3
=12x4-3
=45 square meters

The length of a rectangle is 2x & nbsp; cm, and the width is 4cm less than the length. If the length and width of the rectangle are increased by 3cm, how much is the area increased? If x = 2cm, what is the increased area?

According to the meaning of the question: (2x + 3) (2X-4 + 3) - 2x (2X-4) = 4x2-2x + 6x-3-4x2 + 8x = 12x-3, when x = 2, the original formula = 12 × 2-3 = 21 (cm2), a: the area is increased by (12x-3) cm2, when x = 2cm, the increased area is 21cm2

The length of a rectangle is 2xcm, and the width is 4cm less than the length. If the length and width are both increased by 3cm, how much will the area of the rectangle increase?
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Width is 2x-4cm, so area = 2x (2X-4) = 4x & sup2; - 8xcm & sup2; length and width are expanded by 3cm, length 2x + 3, width 2X-4 + 3 = 2x-1, so area (2x + 3) (2x-1) = 4x & sup2; + 4x-3, so area decreases (4x & sup2; + 4x-3) - (4x & sup2; - 8x) = 4x & sup2; + 4x-3-4x & sup2; + 8x = 12x-3cm & sup2