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2 years ago

3) Aaron and his friend Bobby went school shopping and bought pens &

Mathematics

1 answer:

Nastasia [14]2 years ago

5 0

Answer:

3 pens.

Step-by-step explanation:

x+y=7 where x is # of pens and y =# of pencils

3x + 2y= $18

from first equation, x=-y+7 so substitute that into other equation

3(-y+7)+2y=18

-3y+21+2y=18

-y=18-21

-y=-3

y=3

now replace y =3 into first equation

x+3=7

x=4

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Which angles are right? Check all that apply

Hitman42 [59]

Answer:

If I remember correctly, right angles are 90 degree angles. So the answers would be A. B. and C.

Step-by-step explanation:

If you see the little box on the angle, that means it's a 90 degree (right) angle.

5 0

2 years ago

Read 2 more answers

The diagram shows a prism.

telo118 [61]

Answer:

Total surface area of the prism = 920 cm²

Step-by-step explanation:

Given prism has 2 similar triangular surfaces and 3 rectangular surfaces of different dimensions.

Area of one triangular side = $\frac{1}{2}(\text{Base})(\text{Height})$

Area of 2 similar sides = Base × Height

= 8 × 15

= 120 cm²

Area of rectangular side with dimensions 17cm × 20cm

Area of the side = 17 × 20 = 340 cm²

Area of the second rectangular side with dimensions 8cm × 20cm

Area of the side = 8 × 20 = 160 cm²

Area of third rectangular side with dimensions 20cm × 15cm

Area of the side = 20 × 15 = 300 cm²

Total surface area of the given triangular prism = 120 + 340 + 160 + 300

= 920 cm²

6 0

2 years ago

If c=25 and B=75 degrees, find a. Round to the nearest tenth.

worty [1.4K]

Answer:

a=6.9

Step-by-step explanation:

Since you know that C is a right angle, you can use the Law of Sines to find a. The first step is to find the size of the angle A, which is 180-74-90=16. Now, you set up a ratio that involves 3 knowns and one unknown to get $\frac{\sin(90^\circ)}{25} = \frac{\sin(16^\circ)}{a}$ , which after cross multiplying yields $a=\sin(16^\circ)\cdot25\approx 6.9$ . PM me if you have any questions?