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A rectangle has length (x+3)cm and width (x-2).Given that it's area is 50cm2,find the dimensions of the rectangle

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Answer:

length- 10cm, width- 5cm

Explanation:

You want to convert this into an algebraic equation.

Since a=lw, in this case, 50=lw. Subbing (x+3) for l and (x-2) for w, we get the equation (x+3)(x-2)=50.

Using FOIL, we can expand the brackets to make x²-2x+3x-6=50 and collect like terms to x²+x-6=50.

We want all the numbers on one side (to use the null factor law), so we subtract 50 from both sides. This gives x²+x-56=0.

From there, we factorise it, which becomes (x-7)(x+8)=0. (I used the cross method for this)

With the null factor law, one of the brackets must be equal to 0, meaning x-7=0 or x+8=0. This gives x as either 7 or -8.

With measurement, units must be positive, meaning it has to be 7. We can sub this for x in the 2 equations (length and width) to get the answers.

Length=x+3 becomes 7+3, which is 10cm.

Width=x-2 becomes 7-2, which is 5cm.

**This content involves writing, expanding, and factorising quadratic equations, and the null factor law which you may wish to revise. I'm always happy to help!

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