1. If the solution of the equation (a-b) x = the square of A-B is x = a + B, then the relation between a and B is_____ ? 2. Given that the average of a, B and C is 5, and the average of D and E is 6, then the average of a, B, C, D and E is 5_____ ? 3. If 1 / a - 1 / b = 3, then 2A + 3ab-2b / A + 2ab-b=_____ 4. Given that the average of data x1, X2, X3 is a, and the average of data Y1, Y2, Y3 is B, then the average of data X1 + Y1, X2 + Y2, X3 + Y3 is () A.a+b B.1/3（a+b） C.1/2（a+b) D.1/4(a+b) 5. In known trapezoid ABCD, AD / / BC, AE are the vertical lines on the edge of BC, and the perpendicular foot is e. if the trapezoid area is the square of 26cm, the upper bottom ad = 4cm, the lower bottom BC = xcm, and the height AE = YCM, then the relationship between Y and x is () A.y=26/a+x B.y=13/4+x C.y=52/4+x D.（4+x）y=26 6. If the two sides of △ ABC are 5 and 12 respectively, and the other side C is odd, and the sum of the three sides is an integral multiple of 3, then C should be______

1. If the solution of the equation (a-b) x = the square of A-B is x = a + B, then the relation between a and B is_____ ? 2. Given that the average of a, B and C is 5, and the average of D and E is 6, then the average of a, B, C, D and E is 5_____ ? 3. If 1 / a - 1 / b = 3, then 2A + 3ab-2b / A + 2ab-b=_____ 4. Given that the average of data x1, X2, X3 is a, and the average of data Y1, Y2, Y3 is B, then the average of data X1 + Y1, X2 + Y2, X3 + Y3 is () A.a+b B.1/3（a+b） C.1/2（a+b) D.1/4(a+b) 5. In known trapezoid ABCD, AD / / BC, AE are the vertical lines on the edge of BC, and the perpendicular foot is e. if the trapezoid area is the square of 26cm, the upper bottom ad = 4cm, the lower bottom BC = xcm, and the height AE = YCM, then the relationship between Y and x is () A.y=26/a+x B.y=13/4+x C.y=52/4+x D.（4+x）y=26 6. If the two sides of △ ABC are 5 and 12 respectively, and the other side C is odd, and the sum of the three sides is an integral multiple of 3, then C should be______

First question: a ≠ B second question: 27 / 5 (5 * 3 + 2 * 6) / 5 third question: 3 from 1 / a - 1 / b = 3, ab = (B-A) / 3 can be substituted into fourth question: a from [(x1 + Y1) + (x2 + Y2) + (X3 + Y3)] / 3 = [(x1 + x2 + x3) + (Y1 + Y2 + Y3)] / 3 = a + B fifth question: C from trapezoidal area formula: (upper bottom + lower bottom) * high

A math problem,
2, the square of X + 3x + 3 = 5 times the change sign 2, the square of X + 3x + 9
X?
That's 2 and X are together, but the square is above X
The root goes all the way to 9

X = - 9 / 2 or x = 3
Let's change 2x ^ 2 + 3x + 3 = y first
Then y = 5 * radical (y + 6)
Square for y, and then bring in 2x ^ 2 + 3x + 3 = y for X

To solve a mathematical problem,
-1 + [1 / 24 - (3 / 8 + 1 / 6-3 / 4) × 24] / 5
=

-1 + (25/24 - (3/8 + 1/6 - 3/4)*24)/5=5/24