Answer: B
Step-by-step explanation:
To isolate x, you divide both sides by 21
21x=7

x = 7/21
Simplify by dividing both the numerator and denominator by 7
x = 1/3
Since, 1/3 is not an option, B is the correct answer
slope = (y2-y1)/(x2-x1)
= (70-52)/(8-1)
= 18/7
=2.6
point slope form
y-y1 = m(x-x1)
y-52 = 2.6(x-1)
distribute
y-52 = 2.6x-2.6
add 52 to each side
y = 2.6x+49.4
y = 2.6x +49
the initial temperature is 49.4 or about 49
and it increases about 2.6 degrees each week
Answer: Fourth option:
Triangle ZYB is congruent with triangle OWR, by SSS
SSS: Side Side Side, because the three sides are given, and they are congruent