Need help on this khan academy question

56

Step-by-step explanation:

Because there are two sides that equal the same thing (12), that means that this is an isosceles triangle.

That means that the two angles at the bottom are the same.

This means that there are two angles of 62°

Every triangle has angles equaling 180°, so

180° - 62° - 62° = x°

x° = 56°

56°

Step-by-step explanation:

the triangle is issociles because two of the sides are equal. if the triangle is issociles, then two angles formed by the base(the different side length, 10.4) and the to legs(12 and 12) are congruent. that means two angles are 62°. Since all angles of a triangle add up to 180°, use the equation:

m<a + m<b + m<x = 180

62 + 62 + m<x = 180

124 + m<x = 180

m<x = 56

x = 56°

3 1/3 x 2 3/5 = 8 2/3

step-by-step explanation:

just multiply the first number by the second number to get your answer.

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15