Pls help number 18 and 20

Total mass of materials = 4.8kg

For gravel

55% of the materials are gravel

So we have

55/100 × 4.8 kg

= 2.64kg

For sand

30% of the materials are sand

We have

30/100 × 4.8

= 1.44kg

For cement

The remaining materials were cement so we add the masses of both the sand and gravel and subtract it from the total mass

That's

4.8 - (2.64 + 1.44)

4.8 - 4.08

= 0.72 kg

She earns £ 800 per week

She receives a raise of 7.5% which is

100 + 7.5 = 107.5%

So we have

107.5 / 100 × £ 800

= £ 860

She now earns £ 860 per week

Hope this helps you

when studying polynomials, you often hear the terms zeros, roots, factors and x x the multiplicity of a zero is important because it tells us how the graph of the let's look at the graph of a function that has the same zeros

step-by-step explanation:

(-1,-0.5)

step-by-step explanation: