Math plz! show work giving brainlist : d

Twice the sum of a number and 4 is equal to three times the difference of the number and 7. find the number.

The ratio of the measures of the three angles in a triangle is 2: 9: 4. find the measures of the angels

[15 points]find the least common multiple of the expressions: 1. 3x^2, 6x - 18 2. 5x, 5x(x +2) 3. x^2 - 9, x + 3 4. x^2 - 3x - 10, x + 2 explain if possible