Which expression demonstrates the use of the commutative property of addition in the first step of simplifying the expression (–1 + i) + (21 + 5i)? (–1 + i) + (21 + 5i) + 0 –1 + (i + 21) + 5i (–1 + 21) + (i + 5i) –(1 – i) + (21 + 5i)

i think the answer is C, (-1 + 21) (i + 5i)

Step-by-step explanation:

i just took the test and got a 92% but it didnt tell me which ones were wrong. thats my best guess though. i hope it helps!

intensity of the vector is v= √37 ≈ 6.08 units and make angle ∡α ≈ 9.46° with east direction

step-by-step explanation:

required vector is consists of the two componentsvx= 2+4=6 units   and vy= 1 unit and vx ⊥ vywe will use pythagorian theorem to find intensity of the vector vv∧2 = vx∧2 + vy∧2 => v = √vx∧2 + vy∧2 = √6∧2 + 1∧2 = √36+1 = √37 ≈ 6.08 unitsthe angle ∡α between vector and east direction we wil find with tanαtanα = 1/6 => α = arc tanα = arc 1/6 => α ≈ 9.46°

hope this