The angle measure of a straight line is 180°, and so if the you know that one angle off of it is (5x)°, then you know that the other section is (180 - 5x)°.
Because it's an isosceles triangle, there are two identical angles, which happen to be the angles with the measure of (5x - 30)° and (180 - 5x)°.
Since they have the same measure, 5x - 30 = 180 - 5x. Solve:

Thus,
x = 21°.
Part 1: I'm pretty sure B is soluble in water.
Part 2: The data is showing that A isn't soluble at all (probably cause it's solid or a lipid or something) because the amount undissolved stays the same as B changes in solubility.
Answer:
13
Step-by-step explanation:
351 divided by 27 = 13
D. take the number of dollars she has and multiply by .25.
dividing by a number is the same as multiplying by it's reciprocal. since she is dividing by .25, she needs to multiply by the reciprocal (4,) but instead, she is just multiplying by .25.