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Solve algebraically: 6a + b = 16 5a - 2b = 19

b= 16-6a this will be your substitution. 5a- 2(16-6a)=19 now multiply out. 5a-32+12a=19 always remember positive and a negative multiplied is a negative. 17a=51 a= 51/17 = 3 now substitute a 6(3) +b = 16 b= -2
JD
Answered by Jade D. • Maths tutor
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Solve the quadratic equation x^2-6x+5=0

x 2 - 6x + 5 = 0. For simple quadratic equations such as this example we need to factorise the expression into 2 brackets: (x+a)(x+b) = 0. To find a and b we can expand the brackets to give: x 2 + (a+b)x +ab...
WR
Answered by William R. • Maths tutor
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Find the first three terms in the binomial expansion of (8-9x)^(2/3) in ascending powers of x

Rewrite (8-9x)^(2/3) as (8(1-(9/8)x)^(2/3)=4(1-(9/8)x)^(2/3). Now apply the C4 binomial formula in the formula booklet, so: 4(1 - ((9/8)x)^(2/3)= 4[ 1 + (2/3)*((-9/8)x) + (2/3)((-9/8)x)^2 .....]= 4[ 1 - (3/4...
AR
Answered by Anthony R. • Maths tutor
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IB exam question: Let p(x)=2x^5+x^4–26x^3–13x^2+72x+36, x∈R. For the polynomial equation p (x) = 0 , state (i) the sum of the roots; (ii) the product of the roots.

p(x) = 2x 5 + x 4 – 26x 3 – 13x 2 + 72x + 36 i) obtain the sum by using vieta's fomula: for p(x) the sum is hence -b/a hence, sum = -1/2 ii) obtain the product by using the fomula -f/a. This is because the p...
NM
Answered by Niccolo M. • Maths tutor
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The curve has the equation y= (x^3)/(2x-1). Find dy/dx.

To differentiate a function with respect to (wrt) x you multiply the function by the power and then lower the power by one. For example, if f(x)=x^3, then to differentiate you multiply the function by 3 (the...
PC
Answered by Poppy C. • Maths tutor
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