Help solve a few math problems, solve a few math problems, thank you

1 110 ° or 70

2 55° or 70°

4.(1) Equal, because angle 1 = angle 2

So, the angle dab + angle 1 = angle dab + angle 2 i.e. angle BAC = angle dae2) in the triangle abc and the triangle ade.

ab = ad angle bac = angle dae

ac=ae, so the triangle abc is all equal to the triangle ade, so bc=de

5.Because the angle BAC = 82 degrees and AE is the angle bisector, therefore, the angle EAC = 82 2 = 41 degrees.

Because AD is high, in a triangular ACD, the angle DAC = 180 degrees - 90 degrees - 40 degrees = 50 degrees.

So angle dae = angle dac - angle eac = 50 degrees - 41 degrees = 9 degrees (the question is typographed, it should be to find the angle dae).

2）90°+ 1/2 *a°

3）2a°-180°

Happy studying.

1 110 ° or 70

2 55° or 70°

2) 2a°3) a°4 5 questions are a bit problematic.

1.a=70 or 110 degrees must be the complementary angle of angle a) degrees (you set a to x.).Then b=2xc = 6x and then the inner angle and 180 can be made).

Question 1, 2

In the second question, the upper bottom is 2a 2-a=a-2, the lower bottom is 3(a-2), and the waist length is 2a, so the trapezoidal circumference is a-2+3(a-2)+2*2a=8a-8

Question 3, the original selling price is (1+, and the current selling price is profitable.

Solution 1, equation 2x +3kxy+y -6xy+9 without xy term 3kxy-6xy=0

k = 22, from the top bottom is 1 2-2 cm less than the waist, so the upper bottom is a -2 cm long, so the height is 3 a - 6 cm.

Triangle hypotenuse calculation formula = length * width.

Hypotenuse = 3a-6 + a-2 = 4a-8

So the circumference is 2 4a-8 + a-2 + 3a-6 = 2 4a-8 + 4a-83, the selling price.

Profit adoption oh.

Untie. 1.Set up a plan to buy x refrigerators, Taiwan color TV, by the title.

The solution is x=5, which is tested to be in line with the topic.

then plan to purchase the number of color TVs = units).

2.No. Subsidy = 25,000 * 13% = 3,250 (yuan) two refrigerators = 2 * 1,800 = 3,600 (yuan) 3,250 yuan < 3,600 yuan.

Without increasing the actual burden on the county**.

Can't buy two more refrigerators.

A: 1I plan to buy 5 refrigerators and 8 color TVs.

2.Wait for two more refrigerators.