Draw a picture with a ruler, and make an angle equal to the known angle

Draw a picture with a ruler, and make an angle equal to the known angle

① Make ray o'a '
② Take point o as the center of the circle, draw an arc with any length as the radius, intersect OA at point C, intersect ob at point D
③ Draw an arc with o 'as the center and OC length as the radius, and intersect o'a' at point C
④ Take C 'as the center of the circle and CD length as the radius to draw an arc, intersecting the front arc at point d'
⑤ Through point d 'as ray o'b', angle a'o'b 'is obtained

If the value of - 3x & # 178; + MX + NX & # 178; - x + 3 is independent of the value of X, find the value of (M + n) (m-n)

The original formula = (n-3) x & # 178; + (m-1) x + 3
The value of the original is independent of X
The original formula does not contain x terms
∴N-3=0 M-1=0
∴N=3,M=1
Original formula = (3 + 1) (3-1)
=4×（-2）
=-8

If the value of the algebraic formula - 3x & # 178; + MX + NX & # 178; - x + 10 of the letter X is independent of the value of X, find the value of M and n

-3x²+mx+nx²-x+10
=(n-3)x²+(m-1)x+10
Then n-3 = 0, M-1 = 0
The solution is n = 3, M = 1