Select all of the following that are quadratic equations.
3x2 + 5x - 7 = 0
x3 - 2x2 + 1 = 0
2x - 1 = 0
5x2+ 15x = 0
6x - 1 = 4x + 7
x2 - 4x = 4x + 7

, and are quadratic equations.

Step-by-step explanation:

We are required to find the quadratic equations.

Now, as we know,

Quadratic equation is an equation having degree 2 and is of the form .

So, according to the options, we see that,

The equations , and have degree 3, 1 and 1 respectively.

Thus, these equations are not quadratic equations.

Hence, the equations 1, 4 and 6 are quadratic equations.

Angle LIS is congruent to angle DIE making both of them 61°, angle LID and angle SIE are congruent as well. When you add LIS, DIE, LID, and SIE all add to 360°. So 61+61 equals 122. 360-122 is 238. You divide 238 by 2 to get 119. That will be the measure of angle SIE. A triangle is a total of 180° so add up the angles 27° + 119° to get 146°. Subtract that from 180° to get 34°.

34° is the measure of ISE

Hope this helps!