Which expression is equal to 527.471?* (5x100)+(2x10)+(7x1)+(4x10) + (7x100)+ (1x1,000)
(5x100,000)+(2x10,000)+(7x1,000)+(4 x100) + (7x10)+ (1x1)
(5x100)+(2x10)+(7x1)+(4x1/1) + (7x1/10)+ (1x1/100)
(5x100)+(2x10)+(7x1)+(4x1/10) + (7x1/100)+ (1x1/1,000)

Offering 30 if a plus b plus c equals 68 and ab plus bc plus ca equals 1121, where a, b, and c are all prime numbers, find the value of abc. the answer is 1978 but i need an explanation on how to get that.

Twenty points. suppose that one doll house uses the 1 inch scale, meaning that 1 inch on the doll house corresponds to 1/2 foot for life-sized objects. if the doll house is 108 inches wide, what is the width of the full-sized house that it's modeled after? in inches and feet

If m∠abc = 70°, what is m∠abd? justify your reasoning.  using the addition property of equality, 40 + 70 = 110, so m∠abd = 110°.  using the subtraction property of equality, 70 − 30 = 40, so m∠abd = 30°.  using the angle addition postulate, 40 + m∠abd = 70. so, m∠abd = 30° using the subtraction property of equality.  using the angle addition postulate, 40 + 70 = m∠abd. so, m∠abd = 110° using the addition property of equality.