Because angleCBD+angleBDC+angleC=180
so angleCBD+angleBDC=180-angleC=180-82=98
because BC=DC
so angleCBD=angleBDC
so 2 angleCDB=98
so angleCDB=49
so y=29
by Joy Xu,紫馨雪汐
The value of constant a is -5
Further explanation:
We will use the comparison of co-efficient method for finding the value of a
So,
Given

As it is given that
(x^2 - 3x + 4)(2x^2 +ax + 7) = 2x^4 -11x^3 +30x^2 -41x +28
In this case, co-efficient of variables will be equal, so we can compare the coefficients of x^3, x^2 or x
Comparing coefficient of x^3

So the value of constant a is -5
Keywords: Polynomials, factorization
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