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Expand (x-3)(x+7)

FOIL Method: F - First xx = x² O - Outside x7=7x I - Inside -3x=-3x L - Last -37= -21 Add all the results up to get the answer: x²+7x-3x-21 = x²

Answered by Martin L. • Maths tutor

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Find the value of x: 2x^2 - 3x - 4 = 1

2x^2 - 3x - 4 = 1
To solve, we should bring all the terms to one side, and equate the equation to 0. To do this, we should subtract 1 from each side.
2x^2 - 3x - 4 - 1 = 1 - 12x^2 - 3x - 5 = 0

Answered by Prithvie S. • Maths tutor

4283 Views

Why does magnesium have a higher melting point than sodium?

Both sodium and magnesium have metallic bonding between atoms. Outer electrons become delocalised and float freely between the positive ions. The positive ions attract the negatively charged electrons so ...

Answered by Suzie C. • Chemistry tutor

48204 Views

How does temperature affect rate of reaction of an enzyme controlled reaction?

An increase in temperature increases kinetic energy of particles, so collision frequency increases and more enzyme-substrate complexes are formed, therefore rate of reaction increases. The rate of reactio...

Answered by Suzie C. • Biology tutor

14382 Views

If Angela gets 50p change from a £2 coin, how much is 250g of butter? (full details below)

Angela wants to bake a cake. She needs:250g flour250g sugar3 eggs125g butterEach costs:1kg flour 90p1kg sugar £1.206 eggs £1.15250g butter xShow your working.(0.25 x 0.9) + (0.25 x 1.2) + (0.5 x 1.15) + 0...

Answered by Natalie M. • Maths tutor

3286 Views