The cross method is a factorisation method used for quadratics.
Since the equation is in standard form (ax2+bx+c=0) we can factorise using the cross method.
2x2-3x+1=0
Find two numbers that multiply to 2 on the left side and multiply to 1 on the right side. Also, when cross multiplied they should add to the middle term (-3x).
2 and 1 fit the condition for the left side and two -1’s fit the condition for the right side
The cross method is a factorisation method used for quadratics.
Since the equation is in standard form (ax2+bx+c=0) we can factorise using the cross method.
3x2+2x-21=0
Find two numbers that multiply to 3 on the left side and multiply to -21 on the right side. Also, the coefficients of x in the factors, when multiplied by the constants, should add to 2x.
3 and 1 fit the condition for the left side and -7 and 3 fit the condition for the right side
The cross method is a factorisation method used for quadratics.
Since the equation is in standard form (ax2+bx+c=0) we can factorise using the cross method.
-2x2-11x-12=0
Find two numbers that multiply to -2 on the left side and multiply to -12 on the right side. Also, the coefficients of x in the factors, when multiplied by the constants, should add to -11x.
-2 and 1 fit the condition for the left side and -3 and 4 fit the condition for the right side
