Simple operation of 37 * 6 + 21 * 18

Simple operation of 37 * 6 + 21 * 18

37*6+21*18
=37*6+21*3*6
=37*6+63*6
=（37+63）*6
=100*6
=600

As shown in figure (1) in △ ABC, BP bisects ∠ ABC, CP bisects ∠ ACB, (1) if ∠ a = 50 °, calculate the degree of ∠ BPC

∠ BPC = 115 degrees

If vector a = (A1, A2, A3), vector b = (B1, B2, B3), and a = 5, B = 6, a * b = 30, then (a1 + A2 + a3) / (B1 + B2 + B3)=

∵ a = 5, ∵ B = 6, a * b = | a | * | B | * cosa = 30 ∵ cosa = 1 ∵ vector a and vector B are collinear in the same direction, let B = Ka = (k * A1, K * A2, K * A3) = (B1, B2, B3), (k > 0) and ∵ a = 5, ∵ B = 6 ∵ (A1) ^ 2 + (A2) ^ 2 + (A3) ^ 2 = 25 K ^ 2 * ((A1) ^ 2 + (A2) ^ 2 + (A3) ^ 2) = 36