Solve 5x^2 = 10x + 4 , to 2 decimal places.
First rearrange to get 5x2 - 10x - 4 = 0 , by subtracting 10x and 4 from both sides of the equation. Here, we can use the quadratic formula which is x = -b+- sqrt(b2 -4ac) / 2a. In our question a=5 , b=-10 , c=-4. Substituting these into the formula x = - (-10) +- sqrt(-102 -45-4)/2(5) =10+-sqrt(100+80) / 10 =10+- sqrt(180) / 10 So, x= 2.34, -0.34
AP
Related Maths GCSE answers
All answers ▸Solve algebraically the simultaneous equations: x^2 + 3x + 10 = y and; 4 - 2x = y. Give answers as co-ordinates.
The second term of an arithmetic sequence is 7. The sum of the first four terms of the arithmetic sequence is 12. Find the first term, a, and the common difference, d, of the sequence.
How do you solve the quadratic equation x^2+7x+12=0
On a packet of brown rice it says 'When 60g of rice is cooked, it will weigh 145g.' If Katy has 100g of brown rice, how much will it weigh when cooked?'