Question

solve the equation: 7t2-20t+140=0

Answer 1

Step 1 :

Equation at the end of step 1 :

(7t2 - 20t) - 140

Step 2 :

Trying to factor by splitting the middle term

2.1 Factoring 7t2-20t-140

The first term is, 7t2 its coefficient is 7 .

The middle term is, -20t its coefficient is -20 .

The last term, "the constant", is -140

Step-1 : Multiply the coefficient of the first term by the constant 7 • -140 = -980

Step-2 : Find two factors of -980 whose sum equals the coefficient of the middle term, which is -20 .

-980 + 1 = -979

-490 + 2 = -488

-245 + 4 = -241

-196 + 5 = -191

-140 + 7 = -133

-98 + 10 = -88

For tidiness, printing of 12 lines which failed to find two such factors, was suppressed

Observation : No two such factors can be found !!

Conclusion : Trinomial can not be factored

Final result :

7t2 - 20t - 140