Evaluate the expression when x = -1 and y = 4.

Mathematics

2 answers:

Sedaia [141]3 years ago

6 0

Answer: -9/6

Step-by-step explanation:

Substitute the value of X and Y into the equation. Therefore

X-2y

When X = -1 and when Y= 4

-1-2(4)

-1-8=-9

Y-2x

When X= -1 and when Y=4

4-2(-1)

When multiplying 2 negatives it becomes a positive so...

4+2=6

-9,6 would be your answers... hope this helps you!!

Pani-rosa [81]3 years ago

5 0

Answer:

- 7/2 i'm pretty sure

Step-by-step explanation:

substitute x for - 1 and substitute y for 4.

x - 2y = - 1 - 2 (4)

y - 2x = 4 - (2 -1)

then do the math for both of them and it should either be -7/2 or 7/2

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PLEASE HELP

larisa [96]

Answer:

1.) not safe

2.)

$18 \sqrt{3}$

Step-by-step explanation:

1.) given the length of the ladder = 15ft.

and the height to the top of ladder when leaned against a wall is 14.8ft. This all forms a right triangle.

with what we are given we can solve for the angle it creates from the ground to the leaned ladder by using the SOHCAGTOA. Whike we do this keep in mind its not safe for a ladder to create an angle more than 70 degrees.

in this case if we are solving for the angle where the height is opposite we will use SOH. because we know the oposite and the hyp. Sin(theta) = opp/hyp

$\sin(theta) = \frac{14.8}{15}$

$sin^{ - 1} ( \frac{14.8}{15} ) = 81 \: degrees$

therefore not safe.

2.)

your givin 90 and 60. remember all interior angles add up to 180.

therefore 30 would be the unknown angle.

knowing that we use the <u>chart</u> at the top.

across from 30 is 6. so we put that by x. (remember we are doing this to find the height for our area of a triangle formula = base time height devide by 2.)