The right equations are a+c=30 (total number of people) and 8a+c=100 (total amount of money). So answers B and D cannot be right.
a+c=30 can be rewritten as c=30-a and filled into the second one:
8a + 30-a = 100 => 7a = 70 => a=10
That leaves answer A as the right one.
Answer:
The independent variable (x) is the amount of time John fixes a computer. The dependent variable (y) is the amount, in dollars, John earns for a computer.
y-intercept: (0,50)
Slope: 45
A parabola is the locus of points equidistant from the focus and directrix. This means the distance from the green point is the same to the focus as it is to the directrix. The appropriate choice is ...
... B. 7
Check the picture:
Rotating JKL 180° with respect to the origin, and translating it 1 unit up, we get J'K'L'.
That is, the 2 triangles match perfectly.
Answer:
<span>△JKL is congruent to △J′K′L′ because you can map △JKL to △J′K′L′ using a rotation of 180° about the origin followed by a translation 1 unit up, which is a sequence of rigid motions.</span>