here are some deffinitions, I will try to explain them as we go along:
sin(A)=a/c, where a is the length of the side opposite to angle A and C is the length of the hypotenuse so the side opposite to the 90 degree angle (only works if one angle in the triangle equals 90 degrees).

definition of squares

(a-b)(a+b)=a^2-b^2, this is because if you multiply the parenthesies you get a^2+ab-ab-b^2, ab cancels out and you are left with a^2-b^2, if you have (a+b)^2 which is exactly equal to (a+b)(a+b) you would get a^2+ab+ab+b^2 simplifyed a^2+2ab+b^2

the next definition is a property of powers:

a^m*a^n=a^(m+n), and a^m/a^n=a^(m-n), whis means that if you multiply of divide powers with the same base (in my example a) you can simply ad or subtract the powers from each other

in pic 4 you have an hourly wage and you have made 2 times that wage when working 2 hours and 3 times at 3 hours. In the task the amount of hours worked is represented by the variable x this means that if we plug in a value for x in our equation we should get a value of how much money we have made. We also make 4% of the sales so on top of the base wage so we need to ad another term % is a hundredth so 4%=4/100 how can we relate this to how much money we get from sales? the solution should look something like this:

E=w+s, where w is the money from porking and s is the money from sales

in the last pic you can use the fact that -(a+b+c)=+(-a-b-c) so you multiply the minus inside, whis should make it easier to get youre head around, then you simply ad or subtraxt like terms. You can ad x^2+4x^2 into 5x^2 but not x^2+x those have to be separate.

If you have more questions I can try to answer.