I NEED HELP PLEASE

Only the first and fourth cases are straight lines.

Step-by-step explanation:

If the x values have a constant increase (1,2,3,4... etc), a straight line will also have constant intervals in the y-values (4,6,8,10...).

To identify straight lines if the x-values have constant intervals, just check if y-values have also constant (but may be different intervals.

Case (from left to right)

1.

x = 4,5,6,7 (difference: constant = +1)

y =  7,8.75, 10.5, 12.25 (constant difference = 1.75, so straight line.

2.

x = 21, 22, 23, 24 (difference: constant = +1)

y = 98, 75, 56, 37 (differences are 23, 19, 19, so NOT a straight line)

3.

x = -12, -11, -10, -9  (difference : constant = +1)

y = 4, -1, -4, -7 (differences are -5, -3, -3)  so NOT a straight

4.

x = 40, 41, 42, 43 (difference : constant = +1)

y = -18, -22.5, -27, -31.5 (differences are -4.5, -4.5, -4.5, so constant, straight line.

c.   x=2.4cm

step-by-step explanation:

similar triangles are triangles which have the same shape but not the same size. this means their angle measures are equal but their side lengths are not instead they are proportional. to solve, we will set up a proportion and solve.

a proportion is two equal ratios set equal to each other. we form the ratios by finding corresponding sides (sides which match to each other on both triangles by their position). out ratios will be one side of the small triangle over the corresponding side on the big triangle as shown below:

.

to solve the proportion, we'll cross multiply by multiplying numerator with denominator across the equal sign.

final total: 63

step-by-step explanation:

60 times sales tax

60 times 0.05

3

60 + 3

63