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Brynlee
12-30-2013, 05:38 AM
SAT Subject test Math level 2 Vectors

Which of the following is the vector 2a+b given that a=(0,-2) and b=(1,-4)?

(A) (0,8)
(B) (-1,8)
(C) (1,8)
(D) (-1,-8)
(E) (1,-8)

Thanks!

Thomas
12-30-2013, 05:39 AM
Vector addition can be performed simply by adding the corresponding components of the vectors and in order to perform scalar multiplication, you need to multiply the scalar by each component of the vector.
2a+b=2(0,-2)+(1,-4)=(0,-4)+(1,-4)=(1,-8)

Therefore the correct answer is (E)

Hope these help!!

Brynlee
12-30-2013, 05:39 AM
Thank you!!