Answer:
16
Step-by-step explanation:
4+4+7. Based on PEMDAS, this contain only addition, so go from left to right
4+4 = 8. Continue +7
8+7= 15. Then add 1.
15+1= 16.
x=31,y=−61
Put the equations in standard form and then use matrices to solve the system of equations.
5x+4y=1,3x−6y=2
Write the equations in matrix form.
(534−6)(xy)=(12)
Left multiply the equation by the inverse matrix of (534−6).
inverse((534−6))(534−6)(xy)=inverse((534−6))(12)
The product of a matrix and its inverse is the identity matrix.
(1001)(xy)=inverse((534−6))(12)
Multiply the matrices on the left hand side of the equal sign.
(xy)=inverse((534−6))(12)
For the 2×2 matrix (acbd), the inverse matrix is (ad−bcdad−bc−cad−bc−bad−bca), so the matrix equation can be rewritten as a matrix multiplication problem.
(xy)=(5(−6)−4×3−6−5(−6)−4×33−5(−6)−4×345(−6)−4×35)(12)
Do the arithmetic.
(xy)=(71141212−425)(12)
Multiply the matrices.
(xy)=(71+212×2141−425×2)
Do the arithmetic.
(xy)=(31−61)
Extract the matrix elements x and y.
x=31,y=−61
Answer:
31.5 hours studying English
Step-by-step explanation:
2 math hours = 3 english hours
21 math hours = ? english hours
21/2 = 10.5
10.5 * 3 = 31.5
