Radicals and roots on the ACT Mathematics test covers products of square roots, conjugate pairs, and binomials that mix integers with roots.
A student has to multiply radicals, apply the difference of squares to a conjugate, expand a squared two-term radical expression, and then simplify until the result is an integer or a fully reduced radical. Items are usually a compact expression set equal to a question mark, with five answer choices that mix integers and leftover roots.
Common traps include dropping the middle term when squaring, keeping an unsimplified radical, or flipping a sign on a conjugate.
Sample questions
Pick an answer to see whether it is right — nothing is saved, and nothing needs an account.
Question 1Easier
50⋅18= ?
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Answer: C — 30
50=52 and 18=32, so the product is 15⋅2=30.
Question 2Easier
(7+2)(7−2)= ?
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Answer: C — 5
The factors are conjugates, so their product is the difference of squares: (7)2−(2)2=7−2=5.
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