The equations of four lines are given. Identify which lines are perpendicular. Line 1: y=2
Line 2: y=15x−3
Line 3: x=−4
Line 4: y+1=−5(x+2)

lines 1 and 3

Step-by-step explanation:

y = 2 is a horizontal line parallel to the x- axis

x = - 4 is a vertical line parallel to the y- axis

Then these 2 lines are perpendicular to each other

y = 15x - 3 ( in the form y = mx + c ) with m = 15

y + 1 = - 5(x + 2) ( in the form y - b = m(x - a) with m = - 5

For the lines to be perpendicular the product of their slopes = - 1

However

15 × - 5 = - 75 ≠ - 1

The 2 lines 1 and 3 are perpendicular

9 sandwiches per hour

step-by-step explanation:

when we have a rate, we want a 1 in the denominator

27/3 = 9

27 sandwiches/ 3 hours = 9 sandwiches/hour

see explanation

step-by-step explanation:

a

(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )

= 6r + 7 + 13 + 7r

= 13r + 20

b

remove brackets and collect like terms

13 - r - 1 + r

= 12 - r

c

remove brackets and collect like terms

= - 8 - r + 2r - 4

= - 12 + r

d

remove brackets and collect like terms

= 7r - - - 6r

[-   - = - - = - ]

= r -