10 + 2 (3 + 2x) = 0
PEMDAS dictates you solve what is in parentheses first, but you cannot add what is in parentheses since they are not the same "language;" one is an integer and the other is a variable being multiplied by 2 (a coefficient). No exponents here, so we start with multiplying/dividing: Here our multiplication is in the form of distributive property:
2(3 + 2x) becomes 2*3 + 2*2x which is 6+4x. Your equation is now 10 + 6 + 4x = 0. There is nothing more to multiply or divide since we don't know what x is yet., so we can add/subtract same "language" numbers: 10 + 6 is 16.
Your equation is now 16 + 4x = 0, a simple two-step linear equation. We want to find what x equals, so we need to get rid of anything on the side of the equation with x. The first step here is to get rid of the integer by doing the inverse of its operation. Our integer is 16 and it's positive so it's being added. The inverse (opposite) would be to subtract: 16 (- 16) + 4x = 0 (-16). You must subtract on both sides of the equation or it will no longer be equal. The 16's cancel out to zero on one side of the equation while 0 - 16 becomes -16 on the other side and leaves us with 4x = -16. We need to change our 4x to 1x by using the inverse operation. 4x is 4 times x and the inverse of multiplication is division, so we will divide by 4 on both sides of the equal mark: 4x/4 = -16/4. 4x/4 is now 1x or just x (a coefficient of 1 is understood and not written next to the variable) and -16/4 is -4 (a negative divided by a positive is a negative), so x = -4.