Will mark brainlist! if a = 1, find the values of b, c, and d that make the given expression equivalent to the expression below. expression given: (3x^(2)+2x-21)/(-2x^(2)-2x+12)*(2x^ (3)+25x+63)/(6x^(2)+7x-49) expression that need to equal to the given one: (ax + b) / (cx + d) a= 1