What is the value of y? screenshot below

Step-by-step explanation:

it is an isosceles triangle BA = BC and angle B = angle C.

the sum of the internal angles (in a triangle) is 180°, take away the 2 know angles and you will have angle A

180 - 40 - 40 = 100° (angle A)

now we know that 100 = 2y +20 (angle A)

solve

100 = 2y + 20

80 = 2y

y = 40

check

40 + 40 + 2 * 40 + 20 =

180°

The answer is good

3. (5x + 1) - (-10x + 6)

simplify the answer choice. combine like terms. remember to distribute the negative to the terms inside the second parenthesis. also remember that two negatives = one positive, and one of each sign = negative.

- (-10x + 6) = + 10x - 6

simplify. combine like terms:

5x + 1 + 10x - 6

5x + 10x + 1 - 6

15x - 5

∴ it is your answer

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step-by-step explanation: