When there are no special grouping symbols, math problems are solved from left to right. Although there are other important rules about the order in which you do the operations (addition/subtraction/multiplication/division) in a math expression or equation, this lesson will focus on grouping symbols. The rest of the order of operations rules will be explained in the Determining Order of Operations lesson. To help prevent confusion as you learn how to use the grouping symbols, this lesson will only use addition and subtraction.
(X-10)(X-10)
You need to first multiply out the brackets. So, first times X by X, which makes x^2 . Then do -10 x -10 which makes 100. You then need to multiply the X within the first bracket with the minus 10 in the second bracket which makes -10x. Do the same but with the -10 from the first bracket and the X from the second which again makes -10x. So altogether you have x^2-10x-10x+100. This can be simplified down to x^2-20x+100. You then do the same thing for the second question :)
Answer:
0.8914
Step-by-step explanation:
You want to find the z-values associated with the x-values:
z = (x -μ)/σ
z1 = (57 -90)/12 = -2.75
z2 = (105 -90)/12 = 1.25
Look up these values in a probability table and find the difference of the table values.
p(z < z1) ≈ 0.00298 . . . . from a table or calculator
p(z < z2) ≈ 0.89435 . . . . from a table or calculator
p(57 < x < 105) ≈ 0.89435 -0.00298 = 0.89137 ≈ 0.8914
D) GH≈JK
Reason: Both arcs equal 80° and are vertical angles.
