从正方形的一半减去一个数字得到的结果是11.数是多少?
两个解是:1 + -sqrt(23)解释问题,用x表示数字,然后:1 / 2x ^ 2-x = 11将两边乘以2得到:x ^ 2-2x = 22转置和从两侧减去22得到:0 = x ^ 2-2x-22颜色(白色)(0)= x ^ 2-2x + 1-23颜色(白色)(0)=(x-1)^ 2- (sqrt(23))^ 2 color(white)(0)=((x-1)-sqrt(23))((x-1)+ sqrt(23))color(white)(0)=(x -1-sqrt(23))(x-1 + sqrt(23))所以:x = 1 + -sqrt(23)
假设你在一个数字中加2,减去5,然后乘以3.结果是24.数是多少?
数字为11设数为x,则(x + 2-5)* 3 = 24或(x-3)* 3 = 24或3x - 9 = 24或3x = 24 + 9或3x = 33或x = 33/3 = 11数字是11 [Ans]
半数和6的总和的十倍是8.数是多少?
X = 58/5让未知数字由x表示将问题分解为其组成部分:10次: - > 10xx总和: - > 10xx(?+?)半数: - > 10xx(x / 2+?)和6: - > 10xx(x / 2 + 6)是8: - > 10xx(x / 2 + 6)= 8'~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 10(x / 2 + 6)= 8将支架乘以5x + 60 = 8从两侧减去60 5x = 58将两侧除以5 x = 58/5