Need help with a few of these

Q1 Factorise this expression

bx + by +mx + my

Q2 make the symbol in brackets the subject

t = 2(pie) sq2 l

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g

(pie) = pie symbol

sq2 = square root

Make l the subject

Q3. Same question again make the symbol in brackets the subject

p-mg = mv(sq)

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r

Make M the subject

and (sq) is squared

Q4. Simplify the expressions

a(2) x a(3) x a(-5)

The number in brackets is the power

and square root 9a(4)b(2)

Thank you very much all!