The -1 means that y = -1, so point is one unit below the x-axis. In (5, -1), the x is positive, which could put the point in either the first quadrant or the fourth. With the y being negative, however, it means that the point is in the fourth quadrant. Those are your 2 true statements.
Ur gonna have to pick an equation and solve for a variable.
2x - 2y = 6
2x = 2y + 6 ...divide everything by 2 because u want x by itself
x = y + 3
now we sub y + 3 in for x in the other equation
14x - 2y = 78
14(y + 3) - 2y = 78...distribute thru the parenthesis
14y + 42 - 2y = 78...subtract 42 from both sides, cancelling the 42 on the left
-42 -42
-----------------------
14y - 2y = 36 ...simplify
12y = 36...divide by 12 on both sides, cancelling out the 12 on the left
y = 36/12
y = 3
now , we already know that x = y + 3...and we know y = 3...so sub in 3 for y and solve for x
x = y + 3
x = 3 + 3
x = 6
solution is (6,3)
it is always a good idea to check ur answer by subbing it into one or both of the equations to see if it is correct
2x - 2y = 6......(6,3)...x = 6 and y = 3
2(6) - 2(3) = 6
12 - 6 = 6
6 = 6 (correct)
so yes, ur solution is (6,3)
Answer:
50%: day 13
100%: day 26
Step-by-step explanation:
We are given two days and the amount of the moon that is illuminated. The two days are points on a straight line.
(1, 0.02), (2, 0.06)
y = mx + b
m = (0.06 - 0.02)/(2 - 1) = 0.04
y = 0.04x + b
0.02 = 0.04(1) + b
b = -0.02
y = 0.04x - 0.02
We want y = 50% = 0.5
0.04x - 0.02 = 0.5
0.04x = 0.52
x = 13
y = 100% = 1
0.04x - 0.02 = 1
0.04x = 1.02
x = 25.5
